Actually sliding will work. You mention a "table with a border". If this is a portal and you've selected a visible border for it, it should shrink for you just fine. Sliding object have to be set up just right, they won't expand--only shrink--and the effect is only visible in preview mode or when you print the layout to hard copy or a PDF.
If this is a portal that you are using, you can set up a list view layout based on your portal records and place fields from your parent (invoice) record to get a simple layout that is fully flexible--shrinking or even expanding to multiple pages as needed.
Does this mean in FMP 10 portals will not shrink in LIST Mode? (I.e. they only shrink in PREVIEW Mode and when printing?) Thank you.
For all objects set to slide up, including portals, the slide/shrink is only visible during preview/print/PDF.