An adjustable table needs a wardrobe of tablecloths to match each of the table's lengths, unless you know how to fold a long cloth to fit a shorter table. You can purchase cloths that fit your table's largest size and take a large tuck in each end to fold in the excess length when your table is shorter. The tucks are held in place with straight pins. Use a soft vinyl table pad underneath, or a table topper on top, to help hide the folds.
Measure the length and width of the table. Measure the length and width of the cloth.
Subtract the width of the table from the width of the cloth, and divide the resulting number by two. This gives you the amount of overhang on each side of the table.
Add two times the amount of the overhang to the length of the table to calculate the desired length of the tablecloth.
Subtract the desired length of the cloth from the actual length of the cloth. Divide the difference by four to determine the size of the tucks.
Place the table pad on the table. Center the tablecloth over the table pad.
Measure the length of the tuck you calculated from the end of the table straight down toward the floor on the end of the cloth that needs shortening. Mark this point with a pin on every corner.
Measure the same distance down from the first pin, and mark this with another pin.
Grasp the tablecloth at the top two pins on one end of the table, and pull the fabric under the cloth on top of the table until the second pin is even with the edge of the table. You will be forming a large tuck of fabric under the top surface of the tablecloth. This step is easier with two people.
Pin the fabric in place along the sides of the tablecloth on the underside of the fabric. Tuck and pin the cloth on the other end of the table in the same way.
A short tablecloth or a runner will help hide the bumps from the folds. Buy one long vinyl table pad, and cut it to fit each length of your table. The cut off sections can be taped back on with masking tape when you need them. You do not need to pin the folds on a paper tablecloth.
Do not place pins in direct contact with your table; they will scratch the wood.