It's my opinion that most laughter is social. Like when you're watching a comedy in a movie theater and people are just laughing and laughing and laughing, whereas you know that if they were seeing it at home, they'd be completely silent.
Since reading is a solitary activity, even the funniest books rarely elicit audible laughter.
Tom Jones is the exception.
Henry Fielding's 1742 novel is absurdly funny. For instance, take this passage:
Mrs Deborah, having disposed of the child according to the will of her master, now prepared to visit those habitations which were supposed to conceal its mother.
Not otherwise than when a kite, tremendous bird, is beheld by the feathered generation soaring aloft, and hovering over their heads, the amorous dove, and every innocent little bird, spread wide the alarm, and fly trembling to their hiding-places. He proudly beats the air, conscious of his dignity, and meditates intended mischief.
...The sagacious reader will not from this simile imagine these poor people had any apprehension of the design with which Mrs Wilkins was now coming towards them; but as the great beauty of the simile may possibly sleep these hundred years, till some future commentator shall take this work in hand, I think proper to lend the reader a little assistance in this place.
It is my intention, therefore, to signify, that, as it is the nature of a kite to devour little birds, so is it the nature of such persons as Mrs Wilkins to insult and tyrannize over little people. This being indeed the means which they use to recompense to themselves their extreme servility and condescension to their superiors; for nothing can be more reasonable, than that slaves and flatterers should exact the same taxes on all below them, which they themselves pay to all above them.
What an absurd interlude! He makes a fairly simple simile, and then he's like, "Hmm, just in case you didn't get that simile, I'm going to explain it! It's about birds, you see! And about how big birds terrorize and devour little bird! And in this case the little birds are the villagers! DO YOU GET IT?!?!"
Or here, when Fielding is describing the novel's heroine, he writes:
She was most like the picture of Lady Ranelagh: and, I have heard, more still to the famous dutchess of Mazarine; but most of all she resembled one whose image never can depart from my breast, and whom, if thou dost remember, thou hast then, my friend, an adequate idea of Sophia.
But lest this should not have been thy fortune, we will endeavour with our utmost skill to describe this paragon, though we are sensible that our highest abilities are very inadequate to the task.
Up there, he's basically saying, "The person that this heroine most resembles is my (Henry Fielding's) dead wife. So if you've ever seen her, then just picture her."
I found that to be laugh out loud funny.
The whole book is so warm and so humane. It's full of tons of moments like this. For instance, there's a part, early on, where Fielding implies that Squire Allworthy has done something nefarious to Tom Jones' mother. But then Fielding is like, "Whoah, hold up, let me clear everything up here! Squire Allworthy is the good guy. He never does anything bad in this whole book."
Or what about the part when Fielding is like, "Hey, if you've got any kind of heart, you might not want to read the ensuing description of Sophia, because she's so awesome that she might RUIN ALL OF WOMANKIND FOR YOU."
Hard to believe that this book is almost three hundred years old! It doesn't feel a day over one hundred and fifty.