Books can be a great topic of conversation. Most professionals read (even if they have gone digital and prefer ebooks or listening to audiobooks over the real thing). Books can also be a great thing to recommend or gift to networking contacts or even colleagues.
“I saw this and thought of you” can speak volumes, particularly if you hit the nail on the head.
Of course, this is easier to do (and perhaps seen as more acceptable) if you have recently discussed books with this particular contact and / or know what type of books they like.
If it is a contact that you don’t know particularly well and you don’t feel confident enough gifting or lending them a book then why not simply make a recommendation or offer to send them the book, and if they say yes, bring it with you the next time you see them.