When writing a book in a Minecraft Realms Server. The player is not counted as doing anything, this can lead to a very frustrating action that means that if the player is kicked for being idle (something that for some reason is not an optional feature) they will lose all pages they have just written in the book.

Couple this with there being no flags for Minecraft to save a book unless "Done" is clicked and it seems like a bug that should be addressed. i personally was just in the middle of writing a 14 page book about the history of the server for future players and I was disconnected on my own server for being idle. This caused the book to revert to page 3.
It was so frustrating that I'm not even going to bother to write another copy.

The ideal way to fix this would have the game save a book every time a new page has been created and has text on it. The other way is to make Realms' annoying mandatory idle timeout optional.