Overview: If you submit an edit to the tags, description and source field of an image without any change, it shouldn't count to your tag edits.
Usefullness: Sometimes people accidentally hit enter right away, or they may have attempted to remove a tag that was being implied by anothing one. This would some of the bloating of that number.
Affected pages: https://e621.net/post_tag_history

This sometimes doesn't happen to me. I accidentally hit enter and it doesn't count as a change, with the tag history unaffected. Could it be a bug instead?

I've reported this before, somewhere.

Siral_Exan said:
This sometimes doesn't happen to me. I accidentally hit enter and it doesn't count as a change, with the tag history unaffected. Could it be a bug instead?

Hmm. Maybe it's only when you try to remove an implied tag, then. Unfortunately, the system may not be able to recognize immediately that no change happened.

Lance_Armstrong said:
I've reported this before, somewhere.

Not the easiest thing to search, regrettably.

Furrin_Gok said:
Maybe it's only when you try to remove an implied tag, then.

Tag type changes definitely get recorded as "no-change" edits.

hslugs said:
Tag type changes definitely get recorded as "no-change" edits.

Well I sometimes change those via the actual tags list instead of an image's tags, so it shouldn't count anyways.

Even if there is a performance hit to fix this problem, at least it reduces the amount of unnecessary entries in the database.