Monster Life Walkthrough

I thought that was what it might be for but my book is completely blank no matter what I put in. I have 10 monsters on my farm and it's still blank.

I was a bit confused about this at first, too.
At the top left of the Monster Dictionary, there is a 'Search List' and you can see the two lists for the search criteria. Anyways, next to that there's a Search Button. You've got to press that button for the list to update itself.

I assumed at first that it would make sense for it to automatically update when you select options on one of those two lists, but you need to manually press the search button for it to update.