Know-It-All: The Little Book of Essential Knowledge by Elizabeth King Humphrey
This is one of those books everyone should have in the house, especially if there is debate over Trivial Pursuit questions, or for someone who likes to know a little bit about everything (which, strangely, sounds like a lot of...librarians!)
This is sort of a mini-encyclopedia, made up of ten sections (Understanding the Universe, The Story of the Earth, The Story of Life, Exploring the World, Invention and Discovery, Conflicts of the Modern Age, Structure of Society, Religion and Philosophy, Artistic Endeavors, and Quizzes), with every topic taking up a scant two pages, but written in a really clear, concise language with the occasional sidebar or tidbit of trivia or data, and even pictures to help clarify things.
This is a Reader's Digest imprint, and it totally serves its purpose, while being fun to read to boot! If you have a trivia buff in the family, this is a great book - hardcover, but compact and trade paperback sized. Recommended!