What is an Example of Humor in the 2nd Chapter of the Hobbit?

In terms of narrative structure, this chapter provides a comic interlude as the trolls' ignorance really prevents them from becoming formidable.

Bilbo discovers three trolls who are roasting mutton on spits. They are, of course, significantly larger than Bilbo and summoning his nerves, Bilbo decides to live up to his profession by pick-pocketing. Bilbo reaches for the troll's purse but the bag squeaks: "Ere, oo are you?" and of course, the troll seizes Bilbo. The three trolls, Bert, William and Tom are discussing exactly what a hobbit is and whether Bilbo is worth eating‹and if so, how should he be prepared?

The trolls argue over Bilbo's fate and when they are physically engaged with one another, Bilbo escapes though not without bruises. Unfortunately, the scene does not end here because the dwarves grew impatient while waiting for Bilbo and, hearing the trolls' noises, decided to approach the fire. Trolls hate the sight of dwarves and the appearance of Balin sets Tom and the other trolls on a rampage. It is not long before all twelve of the dwarves are held in sacks and the trolls are contemplating another dinner.