How to get comma separated values by using a query, instead of in a table format (rows)?

In drawloop when you run a query or use tablestart, you get all the details in a list format. For e.g. if you use tablestart on opportunity products, the list is like below.

Product 1

Product 2

Product 3

I want the list output to be comma separated, like this.

Product 1, Product 2, Product 3