My friend removes her pieced tablecloth and uses a plain, 1 fabric, no seams, tablecloth every time she uses the table to eat. I personally would not use goblets/pedestal glasses if they are to sit on seams of a pieced tablecloth. The center of gravity/balance is too high and the glass could fall over very easily. Glasses that are filled all the way down should be fine, unless the top edge is much wider than the bottom base. I would think about making the top as a single fabric and put a border with pieced blocks in it where the sides drop off. Wallah! No problems with tipping.