Separate the 6-inch dowels into pairs of two. Hold each pair together, side by side, with the ends even, and pre-drill three holes through each pair, one inch from each end and one in the middle.
Screw a drywall screw through each hole, firmly attaching the dowels into pairs.
Position each pair of 6-inch dowels laying down in two lines, side by side. Lay four 12-inch dowel on top of the 6-inch dowels, at each end of the dowels, positioning the pairs so that the 12-inch dowels make up two sides of a rectangle box, the end pairs making the other two, with a pair spanning the middle.
Pre-drill through the 12-inch dowels into the 6-inch dowels, one into each dowel of each pair. Screw a drywall screw through each hole.
Now flip the rectangle over and position the remaining two 12-inch dowels on top of one side of each rectangle, aligned with the dowel on the bottom of that side. Pre-drill 12 holes, just like in the last step, and screw in a screw into each hole. These two rectangles will function as the legs of the table, with the sides with two horizontal dowels as the top.
Lay out the four 18-inch dowel rods on a flat surface, positioning them side by side, with the ends even with one another.
Stand each leg, with the top down, across the 18-inch dowel rods evenly, at the ends, and position the long dowels at even distance from one another.
Pre-drill two holes through each leg into each long dowel rod, and screw a drywall screw into each hole.
Flip the laptop computer table over. Place over your legs and set your laptop on the table.