Have you pinched your grapes lately? The berries of table grapes will get much larger if you will remove the bottom third of the bunch. A bunch of grapes has the natural shape of a triangle. Removal of the bottom part of that triangle results in a bunch that is relatively round. If you remove other smaller bunches close by the pinched bunch, the berries will get even larger. You want bunches of table grapes spaced about 12 to 18 inches apart along the vine.