Best Side Table Surface Material

Well, I finished the trailer, but now it's time to move on to the "improvements".
I'm going to build a side table to give me a little more counter space when working in the galley, and I want to know the best surface material.
I have left over aluminum, left over Formica, and left over birch plywood. I'm also open to other suggestions. I want something that will hold up OK to sunlight, and the occasional bit of unexpected rain.
My preference is to use the Formica, as it looks great and would match the galley, but I've had no luck online finding any info about using it outdoors.
Thanks!
--Dean
I'm going to build a side table to give me a little more counter space when working in the galley, and I want to know the best surface material.
I have left over aluminum, left over Formica, and left over birch plywood. I'm also open to other suggestions. I want something that will hold up OK to sunlight, and the occasional bit of unexpected rain.
My preference is to use the Formica, as it looks great and would match the galley, but I've had no luck online finding any info about using it outdoors.
Thanks!
--Dean