sanding glass

If that's what you really want, take it to a sand-blasting shop.

...Jim Thompson

Agreed, you will find that sand papers on an orbital or belt sander will only serve to remove material. Sand blasting or glass beading is the way to achieve an opaque look.

Actually, very fine wet/dry paper with lots of water (use an air driven sander) will sand evenly. However, you'll see whatever pattern your sander creates. IOW, an orbital sander will give you little round rings, etc. You can't really get what you want without sandblasting.

Time to bit the bullet.

You don't like a glass table. ( neither would I )

Replace it !

No matter what you do to it ( sanding, decals, etc. ) it'll still be a glass table, prone to smudges, shattering, etc.

Replace it, and get something you'll like.

When we first got married, we got a big old pine trestle table. Over the years, it's been used for meals, repairs, homework, and crafts projects. It's been dinged, singed, dented, and shows the wear of a thousand uses. It's been re-sanded, re-stained, re-varnished numerous times.... it has our family history. It's a "work table", and we wouldn't have it any other way.

There are glass etching products at craft stores that might do the trick and work a lot better than an orbital sander.

That's a big surface to treat and get it even, with a sander or with etching solution. There are glass companies in this area that advertise in the Yellow Pages that they do custom etching and/or sandblasting. Maybe you can check on this possibility in your area.