This isn't really a struts specific problem. I can think of two approaches:
1. Prepare your data as two collections, one for each table. Display your data as normal and have a radio button which corresponds to each row. When the >> button is clicked, the form is submitted and you have an appropriate action which moves the data associated the radio button to the other collection. Then forward/redirect back to your display jsp (assuming you are using jsp).
Normally trees don't drive trucks. Does this tiny ad have a license?