Is it safe to put a 4'x5' object weighing 1000lbs in my bedroom of my second floor apartment?

A square foot times by 9 is a square yard times that by 30 lbs so a box of 1 yard must not be heavier than 270 lb 4x5 = 20  so 600lb is yor limit and the 1000lb is too heavy and may cause a collapse if the floor is brand new if its aged its dangerous you see its concentrated in the one spot not spreading the weight over the whole floor 

I used to know some very nice people who literally moved out in the night because something heavy they put in their rental house caused extensive structural damage--the room addition in which they placed their queen-sized waterbed literally separated from the rest of the building, showing sky above and ground below, and tilted at a noticeable angle, too. And even though I believe in personal responsibility, I kind of understand. I worked with the woman, and the repair would have cost her six months of earnings at a minimum.

They were putting about 1500 pounds on an area of 4800 square inches (the bed's footprint being 60 x 80 inches). At 1000 pounds, your booth weighs about two-thirds as much, but you will be putting its entire weight over a smaller area of 2880 square inches.

I absolutely would not do it without written permission from the landlord or property management company.

Joists/trusses are designated on load per foot basis, so spaced 16" is 1.33 x 10 foot length room x 30 lbs/sf = 400 lb per joist.

The short side of booth measures 4 ft, covers 3 joists, 400 x 3 = 1200 lbs across the full span of the room. 

If it was only 30 pounds on any one square foot, you wouldn't be able to stand anywhere.

Re-imagine your question. Could your room handle four fat people standing on a shipping pallet?