If you just don't want to see them, you can hide them, or if you just want to delete all the automatic tags, you can do that too. You just go to the arrow to the right of the search bar on the tag pane (next to the colours), right-click and choose to 'Hide automatic tags' or 'Delete all'. If there's a few you find useful, you can just rename them to make them manual tags and delete the rest. I generally avoid using automatic tags as library databases tend to have very expansive tags, so I turn off the preference that creates the automatic tags.