Q: Similar phrase to `Let's have a chat...` I've found this on my friend's book - 

Let's have a chat so that we can set the balls rolling

Looks very professional but I couldn't find something similar to this one myself. 
Does anyone help me?

A: A chat is a friendly conversation. "Let's have a chat" means the same as "Let's have a friendly conversation/Let's have a talk." 
So, the whole sentence could be rephrased like this:

Let's talk so that we can make it all start happening.

It's not clear what exactly should start happening, but you should know from the context, since you read the book.
By the way, the idiom is "to set the ball (not balls) rolling." 
