I would have to agree that they are all Nouns.
Definition of a Noun: A person, a place, a thing, or an idea.
Explanation:
I mean I would understand of living things because a dog, trees, and people are and books well let’s be realistic they aren’t although there would be that saying of paper is living because it came from trees which is true but like I said realistically. And for can be eaten,which is true, there are some who eat dogs :(, trees can be eaten like insects (termites) or deers I think that eat bark, and there are people who eat people
:( (Cannibalism). And so overall, I believe Noun is the best option.
Hoped that helped