The episode in which Pip attends the production of Hamlet with the foolishly deluded Mr. Wopsle as Hamlet is humorous. The entire description of Pip's attendance at this ridiculous performance is hilarious. Chapter XXXI opens with this satiric observation,

ON OUR ARRIVAL in Denmark, we found the king and queen of that country elevated in two arm-chairs on a kitchen-table, holding a Court.

Pip chronicles Wopsle's pathetic performance as he is unprepared and completely discombobulated:

The royal phantom also carried a ghostly manuscript round its truncheon, to which it had the appearance of occasionally referring, and that, too, with an air of anxiety and a tendency to lose the place of reference which were suggestive of a state of mortality.

The audience become raucous and hurls vegetables at the farcical performance of the ridiculously pretentious "Mr. Waldengarver" that Pip even has to laugh at "from ear to ear." After the play, Pip tries to leave without encountering Wopsle, but is halted by a man "heavy of eyebrow" and ends up having dinner with the actor who is so unrealistic that he feels his performance adequate. 

There is humour in even in some of the  darkest moments of the novel. I have a fondness for Wemmick and his father, but I particularly enjoyed Pip fainting with fear as the soldiers arrive at the door. He believes they are to take him for assisting the convict, when of course they are innocent to his involvement. There is much humour - and tragedy- in such miscommunication and presumption.

Dickens' characterization really drives much of the humor in Great Expectations.  One really funny scene is the dinner party when Mr. Gargery retells the story of his life to Pip and discreetly ladles gravy onto Pip's plate when Mrs. Gargery keeps getting onto him.