Medieval Fragments has a terrific, well-illustrated post on book shrines: shrines designed to look like books.
Called a cumdach, the book shrine was a kind of reliquary contains pages from books associated with saints, and occasionally first class relics:
Usually quite small, they served as a portable vessel meant for the preservation of a sacred text that represented a direct connection or association to a saint. They were often decorated in metalwork or ivory carvings, with precious stones to symbolize the valuable nature of the object inside, imitating a treasure binding. These ornamented boxes would be used for the swearing of oaths, protection or even healing purposes.
They’re beautiful and fascinating. Check them out.