I am a renter, have horrible white stones, sharp to walk on

If you want soft, take up the rocks and plant grass. Or another option would be to use concrete stepping stones so that the area is level.

Soft under foot? Hmm, they make some amazing artificial turf now, just have to move the stones and level the area for your table

Try putting a load of sand in the area. It will settle down into the rocks, then hopefully add some surface that eliminates most of the sharp pokes. You could ask if you can rake the rocks out (save them) and either grow grass (seeds are cheap), fill with sand, or even small river rock.

since you are a renter before you do anything you must speak to the landlord

Don’t know how level or uneven your area is? But they do make some fairly thick mats out of recycled tires that go together like a puzzle to make whatever size you want that would solve your sharp rock issue at least. Whether their cheap or not will depend on what’s considered cheap for you? Maybe you could find some used ones too?

Another possibility is to buy those square pavers (pretty 'inexpensive) and use the rocks as the "filler" in between the pavers. The pavers can also be painted.

For my suggestion, you'll need a rake to move the rocks aside and some indoor-outdoor carpeting, preferably the nylon kind that allows for water to go through it rather than soak in. Move the rocks to the perimeter of the area with the rake. You can also use it to level any bumps in the underlying soil. Set down the rug and voila! Instant comfort and decor. Happy summer down under!

Have you asked your landlord if you can do this? That's the first thing you need to do. Maybe he'll buy the things needed for you...