But if the elevator on for instance a PA-28 somehow got jammed and won't move anymore, then the trim tab becomes the only elevator you have left and it works in the reverse sense, e.g. trim down to go up.
In a PA28, you will not find an elevator, only a stabilator (the so called 'all flying tail.')
And you won't find a trim tab either, but you will find an anti balance tab, which works in the reverse sense to an elevator trim tab.
Pedantic reply? Possibly, but we need to understand how our aircraft systems work and using the correct terminology is the 1st step.