Oddly/coincidentally, sentence 51 of chapter 7 ties in with the riddle that the hatter sets ("Why is a raven like a writing desk?"):

If my counting's right:

48: “Have you guessed the riddle yet?” the Hatter said, turning to Alice again.
49/ 50: “No, I give it up,” Alice replied. “What’s the answer?”
51: ”I haven’t the slightest idea,” said the Hatter.

The answer to the riddle itself isn't in the book, but Lewis Carroll came up with an answer later: "Because it can produce a few notes, tho they are very flat; and it is never put with the wrong end in front!"

(Or "nevar" backwords, in other words.)

But can't get anything from that to open the zip file. No idea if I'm on the right track or not.