Measure the height and perimeter of your table. Multiply the perimeter of your table by 1 1/2. This will be the amount of fabric you will need to purchase. It will create a normal-sized ruffle, but if you want a more dramatic ruffle multiply the perimeter by 2. Make sure you have enough Velcro to hold the fabric securely around the perimeter of your table.
Cut your fabric to be about 2 inches more than the height of your table.
Fold over 1/2 inch on both long edges of the fabric, and press them down. Fold over another 1/2 inch on the long edges, press, pin and sew the edges down to create a hem on the top and bottom of the skirt. Your skirt is now ready to be gathered. Hem the short ends in this way, too.
Set your sewing machine at the longest stitch length, and run a gathering stitch 5/8 inch away from the top of your skirt. Run another one 1 inch away from the top. When making your gathering stitches, make sure to backstitch at one end of each of these stitch lines. Since you will be working with so much fabric, you may want to create gathering stitches in sections. Divide the skirt into four or five sections, and run separate gathering stitches for each section.
Gather your fabric to fit on the table. Leave enough for the two ends of the fabric to overlap 1 or 2 inches. This will ensure there are no gaps in the table skirt.
Sew the pieces of Velcro around the table skirt. The amount you will need will depend on the size of your rectangular table. Match up the Velcro on your table skirt with the Velcro on your table, and press them together. This will finish your table skirt.