To mention the topic a book deals with, is it correct to say that 'a book talks about something'?

To mention the topic of a book, I can say that such and such a book is about something or that it tells about something.

Can I say that it talks about something?

Ngram-viewer-ing the book is about, the book tells about, and the book talks about indicates that using tell and talk are far less common than be in this context.

ngram viewer: the book is about, tells about, talks about

Talk sounds weird to me because you do not talk to/with a book: language, information only flow one way, from the book to you; reading a book is not having a conversation with it!

You're right to say that books don't normally talk, electronic children's books aside. The phrase the book talks about is a metonymic reference to the author of the book. That is, the book is in a sense the author's monologue and therefore the 'voice' of the author.

So the phrase the book talks about X means the author talks (or writes) about that subject in the book.

Talk sounds weird to me because you do not talk with a book, language, information only flow one way, from the book to you; reading a book is not having a conversation with it!

The phrase talks about is different from talks with. The former refers to a one-way flow of information as you describe, while the latter implies a two-way flow. So there is no inconsistency between saying the books talks about some subject and saying that you're not carrying out a two-way conversation with it.