I wanted to use hammered copper strips in a coffee table and am would like to if there is a way I can keep the copper bright and tarnish free.
There are epoxy type finishes that will prevent copper tarnishing for a long time, but they are not generally available.
Lacquer will provide a reasonable level of protections.
The copper must be clean and completely degreased before spraying on lacquer.
Deft spray lacquer is pretty available. Look for full gloss for metal work.