send his son Herbert to be Pip’s roommate, to help him settle in and be more comfortable.

My father thought you would get on more agreeably through to-morrow with me than with him, and might like to take a walk about London. (ch 21, p. 120)

Herbert is polite and blunt.  He explains to Pip where everything came from and how it is being paid for.  It is not until Herbert has a chance to catch his breath that he realizes Pip is the “prowling boy” and Pip realizes that Herbert is the “pale young gentleman” from Miss Havisham’s.  They understand that they knew each other before when they were children.

Both Pip and Herbert find the coincidence incredibly funny.  Herbert tells Pip why he was there.

“Yes. Miss Havisham had sent for me, to see if she could take a fancy to me. But she couldn't—at all events, she didn't.” (ch 22, p. 121)

Pip is sorry, but Herbert tells him that Estella is a “tart” and Pip can have her.  He tells Pip that Estella “has been brought up by Miss Havisham to wreak revenge on all the male sex” (p. 121).  He tells Pip he will tell him the story of Estella later.

Pip finds Herbert friendly and useful.  He knows enough about London and Miss Havisham to shed light on some questions Pip has, and he is very friendly.  Herbert and Pip get on very well.

After Pip returns to London and reunites with Herbert at Barnard Inn, where they speak of the desires in their hearts, Pip pulls from his pocket a handbill which Joe has given him, and he and Herbert decide to attend Hamlet in which Mr. Wopsle stars as the Prince of Denmark.

So they "head for Denmark" and upon their arrival, Pip and Herbert find the stage and the performers very amateurish. Also, as the play progresses they realize that some of the performers are even ludicrous: the ghost of King Hamlet must carry the script with him as he cannot remember a single line, the queen is a buxom woman who has everything on her hooked together with chains, Ophelia seems to take forever to die, and Mr. Wopsle's sword fight with Laertes is absurd.
The actors are so amateurish that remarks and shouts are elicited from the audience. One man in the audience makes an incoherent remark to Ophelia which brings laughter from the entire audience. Others shout and call out to Mr. Wopsle as he tries to portray a tragic Hamlet:

Whenever that undecided Prince had to ask a question or state a doubt, the public helped him out with it. As for example; on the question whether 'twas nobler in the mind to suffer, some roared yes, and some no, and some inclining to both opinions said “toss up for it;” and quite a Debating Society arose. 

The tragedy becomes more of a farce than anything else as the audience shouts at the actors, ridiculing them and the performance. (These actions of the crowd resemble those at Vaudeville performances in the 1880's, a couple decades after the publication of Dickens's novel, at which audiences shouted and threw things at the performers.) Certainly, Pip and Herbert cannot restrain themselves from laughter.

Pip encourages Herbert to hurry after the play is over so that they will not run into Wopsle and embarrass him more, but a man stops them with word that Mr. Waldengarver--Mr. Wopsle's stage name--would like to see them. When the young men reach his dressing room, they are greeted by the former Hamlet:

“Gentlemen,” said Mr. Wopsle, “I am proud to see you. I hope, Mr. Pip, you will excuse my sending round. I had the happiness to know you in former times, and the Drama has ever had a claim which has ever been acknowledged, on the noble and the affluent.”

In this chapter, Dickens again exemplifies the pretensions of people and the desire of many to aspire to what they perceive as a superior upper class. Chapter XXXI is clearly satirical in its portrayal of Mr. Wopsle, who comes to London and changes his name to Mr. Waldengarver. Believing himself a Shakespearean actor, Mr. Wopsle reveals only that he is a pompous and rank amateur.

Pip and Herbert joined a London Social club for young gentleman known as the Finches of the Grove.

As Pip became accustomed to his expectations, he tried to follow the lead of the other gentleman in his tutoring circle.  Startop suggested that they join a club, and they did.  Pip never realized that purpose of the Finches.

[The] object of [the Finches] I have never divined, if it were not that the members should dine expensively once a fortnight, to quarrel among themselves as much as possible after dinner, and to cause six waiters to get drunk on the stairs. (ch 34)

Pip notes that the members behave foolishly and spend their money foolishly.  From the influence of the Finches, Pip learns a lot of bad habits.  He begins amassing debt by buying things without paying for them.  He has no idea how much money he has access to or how to get it.  He simply bumbles around making bad decisions.

In Chapter XLI of Great Expectations, there are a couple of incidences of irony.  For one, when Pip declares to Herbert that he can no longer accept money from his benefactor now that he knows what and who he is, Pip states that the only thing that he knows he can do to earn money is to become a soldier.  But, Herbert suggests,

"You would be infinitely better at Clariker's house, small as it is.  I am working up toward a partnership, as you know."

Pip, then, remarks,

Poor fellow!  He little suspected with whose money.

The suggestion of Herbert's is ironic since it has been Pip himself who has procured the position for Herbert with a monetary gift from Miss Havisham.  Now, Herbert wants to give Pip a position.

In another instance, as Pip and Herbert both feel aversion towards the old convict, they discuss what plans Pip can make to be free of him.  While they consider this dilemma, ironically, the old goodness of Pip emerges in the midst of his antipathy for Provis and he cannot simply allow Provis to "throw away" his life if Pip rejects him.  So, they seek a plan that will be safe for Provis.

Finally, when the old convict makes Herbert swear to hold secret what he is about to reveal, he makes Herbert hold a Bible which, ironically, he carries with him.  Again, there is the blending of good and evil in this situation as there is in the first example.

When Herbert and Pip first become roommates, in his great desire to become a gentleman, Pip asks Herbert if he will teach him table manners.  Herbert politely replies, "With pleasure...though I venture to prophesy that you'll want [need] very few hints.  Will you begin at once to call me by my Christian name, Herbert?"  Herbert wishes to put Pip at ease by complimenting him, giving him some confidence, and putting them on an equal plane by calling him by his first name.  These gestures are those of one who wishes to be a friend.

Pip describes Herbert as "so unassuming that I felt grateful to him for not being puffed up.  It was a pleasnt addition to his naturall pleasant ways, and we got on famously."   Even when Joe comes to visit and Pip is embarrassed by his awkward behavior, Herbert, a true gentleman, eases the tension by acting the gracious host to Joe.   He even goes so far as to aid Pip in helping the convict Magwitch escape.  Tolerant, fair, and loyal, Herbert always tries to ease Pip's discomfiture--a true friend.