Partial success: If gedit is running along with Psensor on the desktop,
pressing the Esc key and one of the arrowed keys repetitively (back & forth)
in the lower right hand corner of the keyboard causes RAM usage to jump and
jump again and again, up to around 80%, but I could not find a combination
that would cause a crash. Nothing like this happens if Kompozer is also
running.
So the fateful combination today is gedit + Psensor +System Monitor.
While the RAM commotion is going on, raising Kompozer from the taskbar to the
desktop instantly squelches the commotion.