I understand now. Your comment is very good. When you switch back to a
Section with Controls all the horizontal table layout is switched to a
vertical list of controls and labels. This is just the way InfoPath works,
but your comment is well placed. It would be better if InfoPath preserved the
table layout structure and formatting in this particular "Switch To" case.

Now then there is a partial workaround for this. I assume you have column
labels. You can just select that row and copy paste it and not end up with a
repeating table. You can do the same with a "footer" if you have that too.
After that you can add a row below in your new non-repeating table and then
just drag and drop each field into the new table.

This is a bit cumbersome and your other cell formatting will be gone, but
it's better than recreating it completely from scratch.

Oh, by the way, which version of InfoPath are you using?

Thanks, Shiraz