Using a circular saw as a table saw allows for cutting long boards straighter than is possible with a hand-held saw. Although not meant to act as a table saw, the circular saw blade is not that different from the table saw blade as long as you don't need to make high-end precision cuts. Tables are available with pre-cut blade slots in them, or you can create your own using any common, sturdy wooden utility table.
Erect a 3-foot tall, wooden utility table and locate the exact centre by drawing straight lines from each opposing corner to locate the centre point. Measure the distance between the centre point and one of the long table sides with a tape measure. Use this measurement to create two other points on the table to get a horizontal centre line.
Measure 4 inches on either side of the point on the centre line and make a mark at each point. Position a power drill to drill a 3/4-inch hole at the left 4-inch point so that the outer left edge of the bit aligns with the point and drill the hole. Repeat this with the right 4-inch mark so that the right edge of the bit is aligned with the mark and drill another hole.
Draw a line across the top of the two holes, parallel to the centre line. Insert the blade of a jigsaw in the furthest right hole and cut along the lines between holes to cut out the 8-inch, 3/4-inch slot.
Turn the table over and position a circular saw so that the blade and guard stick through the centre of the slot in the table. Place brackets against the saw and attach the brackets to the underside of the table with a screwdriver and 1/2-inch wood screws. Turn the table back upright.
Measure 1-inch points along the face of the two short sides of the table starting at the centre point and working toward the long sides. Make pencil marks at each 1-inch measurement. Use a straightedge to draw lines across the table parallel to the new blade. Position a piece of 1-by-2 lumber cut to fit the exact length of the table. Set this on the table aligned with one of the lines and secure it with adjustable clamps at both ends. This becomes the guide for aligning boards for cuts.
Plug the foot-control extension cord into a wall outlet, and then plug the circular saw into the extension cord. Turn the saw on by pressing the power switch on the unit. Press the foot-control and ensure the saw activates.
Use a regular extension cord instead of the foot-control if desired and just plug it in and remove it when power is needed.
Check the brackets repeatedly for the first few uses to ensure that the brackets and screws are still holding the saw securely in place. Wear safety glasses when cutting wood on the saw. Be careful mounting the drill with the brackets that the screws don't go through to the top of the table.