"If you close your eyes very tight you can imaging you're Wilbur the pig"
It's rather unsurprising that Meggie and Mo even play games which revolve around books- the two they are talking about here are Charlotte's Web by E.B. White and The Sword in the Stone by T.H. White (no relation!)
If you want to test your own literary knowledge, there are more quizzes than you can shake a stick at (including a ridiculously large number of Harry Potter ones) on this website.