contact cement would be a simple and easy way...the issue has to do with how you want to deal with the edges? having a raised edge with the metal being inset is probably the best...on the more advanced side would me one that had formed and finished corners / sides
Do you already have the metal, or know where to get it? If not, I recommend ordering it online. I ordered a sheet of stainless steel for a backsplash to go on the wall above my stove, and it only cost about $15 and was cut to my specifications. I ordered from stainlesssupply.com. They also sell strips of trim that go along the edge so that it isn't sharp. As for how to stick it to the table, I too would probably used contact cement.
P.S. I had seen this post earlier today, then I ate at Chipotle for dinner and saw they have metal topped tables, and it made me think of you!
Or you could paint it to look like metal like this table... http://entriwp.com/2015/06/21/tin-wrapped-coffee-table/
Glue. Super glue gel type sticks real quick.