I'm with the other two. Break room chats never have very satisfying interactions. It always basically trails off awkwardly.

It's an interlude chat. You can't say "have a nice day/evening/weekend" because you'll probably see them again before they leave for that. You can't say "nice talking to you" because you really didn't talk long enough for that to be true.

It's not a real social interaction, it's a passing moment while you get your food/caffeine fix.

There's no generally socially accepted way to deal with these so most people just walk away. The other alternate is looking at 20 million iPhone pictures of their grand children.