Create a square out of two 24-by-4-by-2 inch pine boards and two 20-by-4-by-2 inch pine boards. Place all of the boards on their 2-inch edges with the shorter boards parallel to one another and the longer boards parallel to one another. Rest the 4-by-2 inch sides of the shorter boards against the 24-by-4 inch sides of the longer boards. Apply wood glue where the pieces meet. Screw two 4-inch wood screws through the side of the longer boards into each end of the shorter boards to secure them in place.
Outline a scalloped pattern on the edge of a 30-by-30-by-1-1/4 inch sheet of plywood with a template. Either use a scallop template from the craft store or use a French curve from the hardware store. Trace the shape onto the table. Cut the scallops out with a jigsaw. Sand the cut edges of the design with medium-grit sandpaper.
Place the scalloped plywood on top of the 24-by-24-by-4 inch square from Step 1. Center the plywood on the square. Hammer 3-inch nails through the plywood into the square spaced every 6 inches.
Flip the table over. Place a 27-3/4-by-2-by-2-inch pine post in each inside corner of the square. Apply wood glue where the posts touch the plywood tabletop and the sides of the square. Place a metal L-bracket on either side of the posts and rest the bend of the bracket where the posts and square meet. Secure one arm of the bracket to the post and one arm of the bracket to the square with the included hardware. Space the brackets so they are centered on the side of the square.
Turn the table upright to rest it on the four posts that now are the table’s legs. Fill the nail and screw holes on the outside of the table and tabletop with wood putty and let it dry, according to the packaging directions. Paint or stain the table and legs as desired. Let the paint or stain dry overnight before using the table.