Bibliomancy was a form of divination which was popular in the Middle Ages. First, you picked up a sacred or significant text, like Homer or Virgil or the Bible. You laid the book on its spine, allowing it to fall open. Then you shut your eyes and picked a passage at random from the open page. This passage supposedly revealed something about your future.
When you try it these days there is a chance you’ll get stuck with the copyright page, which is very confusing. I suspect this is how many copyright lawyers found their start.