resizing tables

Ok guys, if you make a table with a % width, what determines which cell is the cell that will repeat itself to fill the new space that is created when the window is stretched?

I wouldn't necesarilly say repeat itself but, if the cells are specified with a width attribute and a percentage they should all resize, but if it's pixels, the won't resize. So basically any table with a percentage or with no width attribute will stretch.

right, I would usually leave one cell without a width attribute and there we go , one repeating cell
but......
If I have a table, 4 cells, row 1 with 4 cells, row 2 with 3 (where the 2nd is colspan of 2). row 3 with 4. It seems that cell from col 2 is the one to repeat whether the width attribute is applied or not.

I may be going about this the wrong way, but I thought Id post here and well, uh, see if ya'll thought I was nuts!
:D