I guess it would work OK but it would take a lot of effort - as already said, you'd be annealing the copper sheet "every 5 mins"! Ideally you'd also need at least one hide-faced mallet (it's what the professionals use), probably 2 sizes, and the cost of the copper sheet would, I guess be quite high.
I also see a problem with the finished table top marking very easily, not to mention denting if someone accidently dropped, say, a glass or cup.
But as an exercise it sounds interesting, and if you were careful in using the table, especially coating it with a tough varnish after polishing, IMO it would look good in the right surroundings.
But personally I can't see any likely possibility of "plating" a table top chemically. I maybe wrong though.
As an addition to what Dennis CA said above about coating steel surfaces for marking out, it's not necessary to use acid, simple copper phosphate crystals (from the chemist) mixed with plain tap water works fine. I use it regularly.