Try “Restore Session” button on the top of the main buttons
In the SQLab where you optimize a SQL statement or generate index alternatives for a SQL statement, there is a Store Session button on the toolbar that saves the information for the current session. You are also prompted to save the information when you exit if you have not already saved it. The session can then be loaded back into the SQLab with the Restore Session button.
Looking at the main button is a restore session; try clicking this .