how to set fixed rectangle size in report using ssrs 2008 .

Question

I am using rectangles that are 8x10 inches and set to page break after to arbitrarily create pages in a report and I have one page that contains a couple tables with 1 to 5 rows in them each, but never more than 5. The problem is that if the tables only have 1 row the rectangle is the correct height and when exported to pdf fits nicely as one page. However, if there are more than 1 rows in the tables it expands the rectangle beyond its pre-defined height and causes an undesirable page break when exported. If I do that opposite and make it fit for 5 it looks ugly when there's only 1 row.

If anyone knows a way to fix the rectangle's dimension I would appreciate the info. Or any other solution to my problem.