Pages force quit frequently on my maxed-out iMac after upgrading to the latest OS

Ever since I upgraded to the newest OS Pages has gone into this force quit almost daily, sometimes twice a day.

All I am doing, normally, is READING and editing stories when the Force Quit icom comes on the screen with the notice about running our of room and even so, it never gives me the option to report the action.

Since my 24" iMac is maxed, I think, that meand, to me, that somehow the OS is taking much more room than it should because that is the only action that happened lately. I have even reduced the amount of open files I have on the desktop.

My computer aleignment is: internal eDrive, external eDrive as bakcuo, two USB A docks for actions that require passing to one of my other computers for whatever reason.

What is going on?

WGB

[Re-Titled by Moderator]

Original Title: Why Force Quit