Why can't it be centered? It needs to be lowered not raised. The bottom of the chandelier should probably be about 34-36 inches above the table. And if the painting stays there it needs to be lowered too.

There may be an issue with a ceiling joist in the way. Hire an electrician instead of a handyman. There are junction boxes that can span lumber, if that's the problem. In my area, handymen are usually not licensed to do electrical, unless they are electricians. If it needs to be lower, then you'll need ample chain and maybe rewire the fixture so electrical wire is long enough.

Or you can swag it. But I still feel there is no reason it couldn't be moved, it will just cost you. But well worth it to have it centered. I would raise it just a tad too so it doesn't block painting as much. Yes the conventional wisdom is 36" above table but there are all sorts of reasons to hang it higher ie its blocking a gorgeous painting or exterior view. I've done it lots of times in beach or marsh front dining rooms so view is open. It looks fine.

Just get a few extra links and swag it on a hook, and lower it to the correct height at the same time. Lower the artwork also. It's okay if the light hangs in front of the artwork - you will see the art when you walk around and also when you are sitting there. Or try to slide the table down if you have room. It doesn't matter if the table is centered on the wall if it is centered under the light.