CLEANUP: applet/table: add an "action" entry in ->table context

CLEANUP: applet/table: add an "action" entry in ->table context

Just like previous patch, this was the only other user of the "private"
field of the applet. It used to store a copy of the keyword's action.
Let's just put it into ->table->action and use it from there. It also
slightly simplifies the code by removing a few pointer to integer casts.