Select Box01 (which is our table) and then click Add.
With Box01 selected in the list on the left, click the Collision Object radio button to define the table as.. well.. as a collision object. All that being done, you can now click on OK.
Back to the scene, click on the Simulate button and wait until the simulation is complete. This may take a while depending on the complexity of the geometry. After the simulation has completed you will have the cloth nicely sitting on your table.