good advice on how to finish above
I have some additional advice on the design. If you make a top like the one you linked, with spaces between the boards, you will find it hard to clean and maintain because food will get caught in the cracks. If you want the rustic look of pallet wood, you can cover the top glass which will be easier to clean. The table you linked looks like it's made from a pallet....it is. If that's the look you want then proceed as you planned.
Personally if I wanted a clean, white easy to maintain table, I'd use a solid core door in 36" width and 6'8" long and finish it as suggested or seal it, and roll on a quality white enamel with a hardener from a TSC, tractor supply outlet or other industrial paint source. I would not attempt spraying on this, your first project.
Here's something similar except for the rounded ends:
You can still use your pallet wood for the legs and other supports.
Last time I priced a solid core door they were around $100.00.
I understand your budget limitations, so you may be able to find a clean door in a salvage shop or Habitat Restore shop. If you want the look as you linked, you can still use the trestles for the legs or sawhorses made from pallets or brackets like this: