do you mean untag (untabble) a file?
Right-click (or Alt-V) gives you the “unTag this file”
REMOVE TABBLES Pop-Up box appears (as you say) and at top it states:
“Untag” name of your file
“Already In” list of tags that the file is in

click the tag (“Already In”) that you want to delete from file
the tag ‘pops’ to the bottom left of the dialog window
click “Remove” at bottom right

maybe I don’t understand your question