This menu is called when you right click on a PGC in the PGC selector. It also selects the PGC (which you can do first with a left click). It contains many frequently used utilities and procedures which are explained in more detail elsewhere.
The popup menu is context sensitive and changes depending on whether you have selected a menu PGC, a title PGC or the FP-PGC.
Right click menu for menu PGCs
Right click menu for title PGCs
Right click menu for editing commands