Adding an Aluminum table to steel trailer NONO or YES

[1v6pony]

So I have a camping trailer I want to add a shelf/table to fold down on the outside, it will be 15in x 8 Ft.
I would like to use aluminum, steel I think, to heavy, but how real is galvanic corrosion in this instance, I will be using a Stainless steel Piano hinge.
I also thought of starboard but that is apx 50lbs
Thanks

 

[USA4X4]

It should be OK if all of your mating surfaces have a coating that is maintained....