Some of the helpful thing you can fo that i believe haven't been mentioned.
* you can basically have an entire marsian colony base in it, so they just send you out, you will always have enough oxygen and when you get to mars you just deploy the robots and what ever tons of thing that needs to run such a place.
* literally infinite power, if you can set up points where thing enter/exit your inventory then even if it is not very far from each other you can easily create a gint magnetic field that can generate a stable clean amount of power
Now for the things that while yes would not be a good thing to do(morally) but it would be fun
* you said that the only retriction was that it couldn’t store living things, live out your despicable me fantasy and steal the moon, or you could also just put on a spacesuit and steal the earth, thats right remember all of the levels you can get from killing over 7 billion humans and animals.
* so we could generate infinite power, but we could also create an infinite length rail gun that can lock on and shoot at anything and reliably say that it will die in the soon furture.
just some of the things my sleep deprived brain can think about.