Is there a way to get rid of it?
Partron22 is correct. Go into album view give the album a rating, then take it away. That will remove the album rating and maintain any existing track ratings for the album. Unfortunately, this database corrupting activity is not a one-time event (i.e., this didn't just happen during an iTunes upgrade). Whatever bug that is causing this will continue to apply bogus album ratings throughout your library—seemingly at random.
I'm not sure why Apple has been unable, or unwilling, to squash this obnoxious bug. Perhaps iTunes has become such a dump they're not able to keep up. I would say that all of their attention has been directed at Apple Music, but they are able to alter the iTunes UI every couple of months, so... I'm a bit concerned that the jettisoning of ratings from the music app in iOS is a sign of things to come on iTunes.