How does Lady Macbeth deal with Macbeth's behavior toward their guests in Shakespeare's Macbeth?
That is, how does Lady Macbeth excuse Macbeth's behavior and criticize him in alluding to an earlier incident?
In addition to the details in the above answer, Lady Macbeth has to do almost the exact same thing she does in Act 3.4, earlier in the play.
In Act 1.7 she comes looking for Macbeth because King Duncan, their guest for the night, has "almost supped," almost finished eating, and Macbeth is no where to be found. This is rude, of course; one doesn't disappear when the king is dining with you. But it also is just the kind of thing Lady Macbeth warns him not to do before Duncan arrives. The kind of behavior that might raise suspicion. She says in 1.5:
Your face, my thane, is a book where men
May read strange matters. To beguile the time,
Look like the time [act how people expect you to act]; bear welcome in your eye,
You hand, your tongue. Look like th'innocent flower,
But be the serpent under't.
In short, Macbeth just keeps messing up, and Lady Macbeth is left with trying to salvage what Macbeth ruins.
At the banquet in the play 'Macbeth' by William Shakespeare, we see Macbeth's madness begin to escalate and we also see the beginning of the end for the relationship between man and wife, Lord and Lady Macbeth. The whole idea of banquets was meant to put guests at their ease (indeed in ancient times the guests would have been so trusting that they would have expected to leave their weapons and shilds in the hallway on the way in - so this is ironic!) In the Macbeth's case they take this one step further, because they are wanting them to be gulled into a false sense of security and not guess anything untoward is happening or has happened. Lady Macbeth has to be the perfect refined hostess, and Macbeth likewise. It is when he realises he has been thwarted that his vulnerable mind cannot deal with it, and Lady Macbeth hastily gets rid of everyone as his mind unravels and starts to become incriminating.
In Shakespeare's Macbeth, Act III, a banquet has been prepared for Ross, Lennox, and others. When Lennox tells Macbeth that a place has been reserved for him, Macbeth replies that "the table is full" (Act III,iv,47), believing that Banquo's ghost sits at his place. After Macbeth asks Lennox and the others who has caused Banquo's ghost to be present--"Which of you have done this?" (III,iv,49), Lennox urges the men to rise because Macbeth "is not well" (III,iv,52), Lady Macbeth tells the guests that Macbeth is often "thus." But, the fit is momentary, and he will soon be well. She urges the others to dine and simply ignore his behavior lest they embarrass him.
Turning to Macbeth, Lady Macbeth asks him, "Are you a man?" (III,iv,59), trying to snap him out of his trance. She continues, "O proper stuff!" (III,iv,73), ridiculing his sight of Banquo's ghost as being as ridiculous as his sight of the "air-drawn dagger." Lady Macbeth tells her husband he is like a woman telling a story before a fire. She exasperatedly tells him that he should stop acting as he is, and be ashamed of acting so. Nevertheless, Macbeth continues to see Banquo's ghost; then, he berates the ghost.
Finally, Macbeth confronts his ghost. but he has broken up the party with what Lady Macbeth calls, "admirable chaos." She has asked them to leave, fearing that her husband will reveal that he has killed Duncan.
You are talking here about events that happens in Act III, Scene 4. Macbeth is at a feast and sees the ghost of Banquo. Only he sees it, so his behavior seems really weird to the guests.
Lady Macbeth tells the guests that her husband has been like that ever since he was a kid -- he gets these seizures at times. So she's trying to get them to think that it is just an illness.
But then she says to Macbeth that he is, essentially, a coward. She says he always gets like this when he is afraid.
As for an earlier experience, she talks about the time just before he was going to kill Duncan when he had the vision of the bloody dagger.
To go along with the comments above, Lady Macbeth doesn't particularly know what is going on with Macbeth at this point in the play. She makes up the fact that Macbeth has had this illness since he was a little boy, a lie that will get the guests off their back and not think anything of it.