Clamp Top Pieces Together
Apply painter's tape to one face of each of the 2x2 oak squares. You will use these oak squares as cauls when clamping the top slats.
Position three or more bar clamps open on a level work surface and position the top slats on the clamps in the pattern you determined and with an inch or so between the parts. Apply glue to the joining edges, butt the parts together with the ends flush and clamp lightly in place.
Position the cauls, tape side against the top slats and butted against the bar clamps, and clamp lightly in place.
Continue to tighten the clamps on the top slats and cauls, making any adjustments as needed. Allow the glue to set.
Remove the clamps, then scrape and/or sand off the glue from the joints. Cut the final top assembly to length using a table saw.