Bibliomancy is the use of books in divination. The method of employing sacred books for ‘magical medicine’, for removing negative entities, or for divination is widespread in many religions of the world
Given my habit of snatching ideas and manipulating them to suit myself I randomly took a small passage from Roald Dahl’s Revolting Rhymes and asked a character from the Your Path Through The Enchanted Forest Tarot deck to play and stimulate an idea for a quirky story.
The Keeper of Spells emerged. When asked how he would feel if some delinquent tot broke in and gobbled up all his breakfast the answer was unequivocal. The little brat should start running because the Keeper would transform into a giant and we all know that while some giants are friendly this one is unlikely to be. He has no time for thieving little wildlings who would be audacious enough to eat his tucker.
Try the exercise with something from your shelves and write your own adventure.