If you don't know what to say, you can always start a conversation with:

A five minute monologue on why you should have aircon off in meetings

You can follow that by asking the person next to you:

What they really think of that awful boss down the hallway.

Why they don't have surgery for their big nose

What is an appropriate sentence for small talk in meetings?

What did you think of the football game on Saturday?

What kind of suit is that? You look like you can hardly squeeze into it?

Has anyone had an argument with their spouse recently?

What is a forbidden topic in small talk before business meetings?

What is a good icebreaker for international business meetings?

Talking about favourite restaurants (or food, colour, car etc.)