For front and back, cut two panels that measure the width of the table by its height, plus 2 inches on all sides (for seam allowance and hems).
For the sides, cut two panels that measure the depth of the table by its height, plus 2 inches on all sides.
For the corner panels that will mask the legs, cut four pieces 8 inches wide by the height of the table, plus 2 inches on all sides.
Double-fold and topstitch the side hems of all panels (but not of the tabletop piece). Pin panels together so outer panels overlap corner panels; stitch 1 3/4 inches from top.
Pin skirt to top piece, right sides facing and raw edges aligned; if necessary, cut a notch in the seam allowance of the skirt at each corner. Stitch 2 inches from edge. Place the skirt on the table to mark length, then hem.
If you already have a tray, seek out a table of matching size. In a pinch, you can cut a piece of plywood the same size as the tray and place it atop a smaller table that sits under the skirt. For the skirt, which has the look of inverted box pleats at the corners, we used matelasse cotton. This skirt is made of overlapping panels that are not joined at the edges, so that the underside of the table remains accessible.