Delete a TextEdit document in iCloud
This seems quite counter-intuitive, but...


In TextEdit, select File > Open…
Press the iCloud button at top left.


Then:


drag the icon you want to delete to the Trash in the Dock
or control/right click the file icon you want to delete and choose the Move to Trash option (pictured below)
or press cmd-backspace (the backspace key is labelled with a left-facing arrow)