Looks like a type of filler panel for the unused slots.
With the GT 1030 card installed, are the other slots open or closed off? If open, that would give dust a way to enter the case.
Personally, I think you're fine to leave it out.
Mike.
You da man! Thank you.
The three vacant slots are blocked with the metal panels.
I agree with your thinking.
My only concern was, if filler....why metal instead of something more benign?
That made me think there was some..l dunno....grounding, or some other issue I might be overlooking.
Your input much appreciated.