Layout of "Review and Submit Order" screen

HELP!! We're almost ready to go live with our site and I've been frantically tying up loose ends this week. I've done a lot of customizing of transaction forms and their pdf layouts -- learning on-the-fly with a lot of trial and error. Yesterday afternoon I discovered the section of my checkout review page which displays a custom transaction field and the item list has become reeeeeaaaaalllly wide. You have to scroll way over to see the pricing info.

I don't know what I did. I've done so much this week, I don't know what to un-do.

If I could figure out where the controls for that section lie, I would know where to go to fix it. But I can't find anything about controlling the layout of that page in Help. There must be a place to adjust the width of these elements, right? (Must be if I was able to screw it up)