Piers Anthony wins by numbers according to my Library Thing, with 56 books, and Marion Zimmer Bradley in second with 39. That doesn’t take into account Stephen King, as I haven’t scanned them in yet, so I don’t know the exact count.
The biggest and fattest is the complete works of William Shakespeare.
I don’t know how to quantify “most knowledge”.
Most Questions is probably “Why Do Men Have Nipples?” And “Why Do Men Fall Asleep After Sex?”, By Mark Leyner and Billy Goldberg, M.D.
And, just for the shiggles, I have 134 Star Trek books.