When I buy a brand new table saw or band saw, I'm as excited as a six-year-old on Christmas morning. The first thing I want to do is rip open the box, plug it in and sacrifice a pine board. (Of course, this is after reading the instruction manual that accompanies the tool thoroughly and properly setting up and tuning the saw!)
The tables on most quality table saws and band saws are cast iron, which is highly prone to rusting. Most of the time, the units are shipped with a special protective grease that needs to be cleaned thoroughly before using the saw, and it is probably a good idea to also apply a protectant to the table before indulging in that first cut.
There are a number of quality lubricant/protectants available on the market specifically designed for saw tables. Any merchant who specializes in fine woodworking tools should have a few different varieties from which to choose. However, if you don't have any on hand on the day that you set up your new pride-and-joy, simply dig through the shelves in your garage and find an old can of car wax.
Carnauba-based paste wax is designed to protect your car's finish from the elements, and it will perform the same task on your saw table. Simply rub it on liberally with a damp sponge and let it dry for a few hours. Then buff it out with a clean cloth (or a buffer, if you have one). Put on a second coat if you feel that it is necessary, but be sure to remove all of the wax out of the miter gauges. You'll want to put on another coat every month or so, just to keep the table in tip-top shape.
One thing to keep in mind: you should never use silicone-based products on your saw tables, as this can leave a residue behind that can interfere with the finishes on some types of wood.