What do people mean when they say coffee table books?

There are a number of definitions out there (and not all of them are necessarily positive!)
For some people the coffee table book is a conversation starter­ something impressive-looking,
designed to get people discussing it. In effect there is an element of making a statement­.
It could be “I’m not a snob and will happily read a blockbuster” or “I have studied this particular subject” or
“I’m someone who is interested in a specific subject and here is the proof”.
For other people a coffee table book is something glossy with illustrations, something that is easy
to pick up and read when you are sitting and enjoying a coffee break. The idea is you enjoy
reading it without necessarily being engrossed by it. In this sense the book is considered the
equivalent of easy listening or a cheesy favourite film that is on TV but you do something else
while you watch it.
The coffee table book has even been referenced in television shows­ the most famous example
being the character Kramer in Seinfeld who pitched “a coffee table book about coffee tables and
you can fold it out to form a small coffee table.”
Therefore in conclusion when people talk about coffee table books they could be referring to a
decorative statement, an easy read or in the case of the fictional Kramer a book you could literally
use as a coffee table!