There's a user on SO (this one, if you must know) doing heaps of edits to old questions, just to remove one tag from them which he feels does not belong. How can we tell him that
Just leave a comment. Editors can be @replied, even when their name does not pop up.
Just leave a constructive comment thanking them for their effort, because their willingness to help is always appreciated. And then explain how they might better perform their edits.
They could spread them out a bit more. There is after all no hurry. And of course they should take the whole post into account, fixing all issues. Doing so will slow you down immediately, because you spend more time fixing each individual post. And seeing a - by now - good post pop up, is not nearly as annoying as seeing something old being bumped with all kinds of issues.
And keep in mind that if these are suggested edits getting accepted, then any "problem" is in a large part due to the reviewers. They could have easily sent a message by rejecting such edits as too minor. If all your edits get accepted, why would you need to change your behaviour? You're doing something right, right?
So just leave a gentle comment. That will usually do the trick.