What is the significance of the banquet scene in Macbeth?

Initially, Macbeth does not agonize over the moral implications of ordering the murder of Banquo and Fleance. He did agonize over Duncan’s murder. He orders Banquo’s murder out of fear. He believes that by killing Banquo, he destroys the prophecy that Banquo’s children will sit on the throne. However, at the banquet, Macbeth’s fear does turn to guilt and he sees or imagines Banquo’s ghost. This is significant because this is the first time Macbeth’s inner conflict is made public. This is when things really start to fall apart for Macbeth.

Macbeth becomes increasingly paranoid about everything. This is reflected externally as well as internally. He begins to think that Macduff’s absence at the banquet might imply that Macduff is plotting his own revenge.

It is also a significant break between Macbeth and Lady Macbeth. He sees the ghost and she does not. She tells his guests that he has a condition so they won't suspect anything. She simply thinks he is thinking too much.

They both have guilt and fear, but this is a breaking point. Remember that in Act III, Scene 2, Macbeth did not tell Lady Macbeth about the plan to kill Banquo and Fleance. “Such things” refers to Banquo’s ghost:

Can such things be,
And overcome us like a summer’s cloud,
Without our special wonder? You make me strange
Even to the disposition that I owe,
When now I think you can behold such sights,
And keep the natural ruby of your cheeks,
When mine is blanched with fear. (3. 4. 131-137)

These lines are also listed as 1409-1415 for the entire play. Macbeth wonders how she can witness such a thing as Banquo's ghost and not be affected by it. She doesn't see the ghost. She thinks he is consumed with fear, which is true.

What is an analysis of the banquet scene in Macbeth?

The banquet scene is both a high point for Macbeth as King of Scotland and the beginning of the end for him.  The banquet is his first celebration as King, and he is joyous, thrilled with his new position, sitting on the throne suits him, he has managed to put aside the horrible images, the haunting images that plagued him right after Duncan's murder.  At the banquet, Macbeth is determined to enjoy himself.

"Macb. Sweet remembrancer! 
Now good digestion wait on appetite, 
And health on both!" (Act III, Scene IV)

But, unfortunately, in the presence of those assembled, members of his court, his wife, surrounded by attendants,and Lords,  Macbeth has a mental meltdown because he sees Banquo's ghost sitting on his chair, of course, no one else sees him.  He becomes so unhinged by the sight of his former friend, now dead, thanks to his orders, that he can't focus on his party.

He can't sit at the table because the ghost of Banquo occupies his seat.

"Prithee, see there! behold! look! lo!
how say you?
Why, what care I? If thou canst nod, speak too. 
If charnel-houses and our graves must send 
Those that we bury back, our monuments 
Shall be the maws of kites. [Ghost disappears." (Act III, Scene IV)

Once Macbeth sees the ghost, it disappears, but it comes back.  And he addresses it again, causing all his guests to look in wonder at him.  Lady Macbeth becomes concerned for her husband, he is the king, and he is making a fool of himself.  So she orders everyone out, and breaks up the party claiming that Macbeth is having one of his spells.

"Lady M. Think of this, good peers, 
But as a thing of custom: 'tis no other; 
Only it spoils the pleasure of the time." (Act III, Scene IV)

This scene, in particular, underscores the fact that Macbeth still has a working conscience.  He killed the king, inspired by the witches prophecy and with additional prodding from his wife, but he still had a sense of remorse after the act.  By the time of the banquet, he has sufficiently recovered his control over his emotions to have a good time.

But his conscience is still working, so it intrudes on his party, because, Macbeth has, technically not by his own hand, murdered again.  This time, his friend, who he perceived as a potential threat to his crown.

All the acts of murder that Macbeth hires killers to commit after he is crowned king are all motivated by fear or paranoia. He is desperate to protect his throne, one would assume that he thinks that he is going to live forever, the way that he tries to eliminate all potential successors to the throne of Scotland.

What is significant about the coronation banquet in Macbeth?

The coronation banquet in Shakespeare's The Tragedy of Macbeth is significant for several reasons. First of all, at the start of Act 3, Scene 4, Macbeth speaks directly with one of Banquo's murderers, confirming that Banquo is indeed dead. The death of Banquo is supposed to be reassuring to Macbeth because it means that Banquo no longer stands in his way of obtaining power, but the reassurance is brief. The knowledge that Banquo is gone lifts worry from Macbeth, but not for long, as Banquo's ghost soon appears at the banquet.

The appearance of Banquo's ghost is also significant because of how the vision of the ghost impacts Macbeth. In the moments before the ghost appears, Macbeth may experience a sense of relief, but it is short-lived. Whether the ghost is a figment of Macbeth's guilt or a supernatural being haunting Macbeth, the significance of the ghost's appearance is undeniable. Macbeth will never be free of his crimes as long as other elements out of his control (like his conscience or the free will of a ghost) continue to show themselves.

Macbeth's reaction to the ghost is visible to others, like Ross and Lennox, and Lady Macbeth has to try to repair the damage done to Macbeth's credibility when Macbeth begins to speak in riddles directly to the ghost of Banquo. These moments are significant because others are able to observe the crumbling of Macbeth's strength and character. His downfall begins just as he is crowned king, in a dramatic and ironic twist.

The coronation banquet in Act 3, Scene 4 of Macbeth seems intended to dramatize the fact that Macbeth and his wife, though they have attained the royal status they so badly wanted, will never be able to enjoy the advantages they thought it would bring. Everything is set up for an evening of regalement and everyone present seems prepared to honor the new king and queen with the greatest show of respect and affection, regardless of what they might really think of them. All of these distinguished men are on their best behavior. However, Macbeth can no longer get any satisfaction or enjoyment out of anything. He is haunted by his guilty memory of what he did to steal the crown and is further haunted by his knowledge that he had his good friend Banquo murdered. Macbeth is also troubled by the knowledge that Banquo's descendants are apparently destined to inherit the Scottish throne rather than his own offspring, should he manage to produce any. Poor Lady Macbeth has gone to a great deal of trouble to arrange a nice party for all of these important men. We have seen how the best-laid plans of hostesses are often thwarted in this life because of arguments or disturbances of one kind or another. She tells her husband:

My royal lord,

You do not give the cheer. The feast is sold

That is not often vouch'd, while ’tis a-making,

’Tis given with welcome. To feed were best at home;

From thence the sauce to meat is ceremony;

Meeting were bare without it.

The great satisfaction this husband and wife expected to experience by becoming king and queen never happens. It is nullified from the very beginning. They are two lonely, isolated people without a single friend in the world. Our great expectations are often disappointed in this life. In the end, Macbeth realizes he made a terrible mistake, as shown in Act 4, Scene 3:

I have lived long enough. My way of life

Is fall'n into the sear, the yellow leaf,

And that which should accompany old age,

As honor, love, obedience, troops of friends,

I must not look to have; but, in their stead,

Curses, not loud but deep, mouth-honor, breath,

Which the poor heart would fain deny and dare not.