I bought a nice Rigid brand table saw a few years back. I was so careful to spray it down with WD40, or wipe it down with motor oil. This worked pretty well, but some rust spots developed despite my best efforts. Just happens my face really sweats in hot weather. At times latge drops of salty sweat would drop on the table as I leaned over it. I usually wiped them off promptly, but sometimes missed them! & a rust spot developed almost instantly. So one day to I sanded it down a bit and applied a thin coat of varnish with a good quality brush. It's not as slippery as bare, polished/regularly used steel, but no more rust worries. When the varnish begins to wear off, I'll sand it down & varnish it again. Works for me.
Glenn F. (NE WI)