This is woodworking and OP's talking about the table on a scrollsaw, not
even a TS or a jointer, for heaven's sake.

True.

He's not going to remove enough material w/ a 200+ grit to get to a
clean surface (ignoring staining, of course, as I already mentioned
earlier) to possibly matter...a fraction of or a mil will be impossible
to discern in functionality (as would several mils in reality on a
scrollsaw). Getting a jointer table severely out of whack is a
different animal, of course...

I barely took off anything and when the rusted area was almost down to
the level of the rest of the surface, I sanded the entire surface. I
got this unit second hand but it's in great, almost new, shape. I
doubt the miniscule amount of metal I sanded off will ever make a
difference. Now I just have to remember never to oops again.

Precision is good but folks tend to get way over-paranoid on tolerances
w/ woodworking--heck, the wood itself will move more than you're talking
about here just from the time you mill it before it's assembled not to
mention how far it will then go when glue is applied and it soaks up
that moisture.
dpb

I get a lot of this from some people. I wanted to make a custom rest
for my lathe for some special projects and was telling my neighbor
about it. He kept insisting I would have to have it made in a machine
shop due to tight tolerances. I tried to explain to him this is a wood
lathe and not a metal lathe but he refused to get the idea until the
rest was made and he saw how it worked. He never said another word
about tolerances after.