Why is The Giver allowed many books while the other citizens are allowed only three? How are books and memory related?

The Giver is the only person in Jonas’s community that holds on to knowledge, information, and past memories. He is the keeper of memories and is therefore called the Receiver. He calls himself the Giver, however, because he transmits these memories to Jonas.
Knowledge and memories are hidden from everyone else because they are often disturbing, uncomfortable truths that everyone would rather forget. For this reason, everyone except the Giver is only allowed three "safe" books.
Since the Giver is the keeper of all information and knowledge, he needs to have access to every book that society has. He cannot get the information anywhere else, so it is essential that he be allowed to consult books.
Books are also keepers of memories, written testimonies of events, thoughts, and actions. Books are full of history, and history often records wars. Even though the dystopian society in which Jonas is living does not want anyone to remember wars or know about them, they still realize that it is fundamental knowledge to have in order to avoid repeating the mistakes of the past. For this reason, one person must take on the role of Receiver of Memory.