The info presented in the Book template is kind of essential to making individual spell pages unique as the point of those pages is to provide more detailed info about the spell. Therefore I recommend that we create a better version of the Spell template that integrates the info from the Book template more smoothly. The way the two templates collide at the top of the page doesn't look too appealing.
This is NOT a recommendation to remove the Book template and merge it with Spell, there are other books that are not associated with spells. But almost all spells are associated with a book.