I wonder what the book is.
I suspect it might be the sum total of mankind's collected philosophy. Every question ever asked, that sort of thing. Any mind exposed to it is instantly satisfied with regard to everything it could possibly ever want to know. Sort of a futuristic wikipedia that ends up sapping your will to continue existing, created with the best of intentions, perhaps as a teaching/learning tool, but with horrifying side effects unknown to its creators.
A lot of the fun in being human and alive is not knowing all the answers. With how dumb we are, we stumble drunkenly through the universe, occasionally inventing something new like x-ray telescopes to see it in ways we can't with our eyes. Having all the questions answered would be like eating the tastiest, most satisfying meal in the universe - but what do you have for breakfast the next morning?