My apologies, I was under the impression we were discussing the Power Store implementation and using the tools with that.
For the product listing page that is part of the eCart sample store you will need to make the edits directly on that page. To make the layout work with two columns you will either need to manually edit the display to add in the extra column, then adjust the code to write to one column then the next, or you can use the DataAssist tool to create the horizontal loop for you. If you have purchased a suite of tools you will likely have this tool available to you.
Doing this manually requires the use of a nested loop, the outer loop will write the new row, and the inner loop will write the details to the columns.
