Well, Lenamare’s book is a very specific kind, its a macguffin. Essentially an object/person that the characters covet but do no actual thing in the plot. Its main purpose is to make the characters move. Many examples abound: the fountain of youth (many fantasy stories especially ones about the knights of the round table), pokemon badges (pokemon franchise), Kidnaped children/son/daughter (many stories like The Great Mouse Detective). All these things do is provide something for the characters to acquire which, adding some antagonist, creates tenion and conflict. Otherwise it have no other great purpose.
Well, I do know a phonebook do become a plot device. Remember Terminator? Terminator robot killed the victims in accordance to phonebook listing.