I've seen several folks add the metal tiles as backslash. I did read a post, not too long ago, about putting ceramic tile in campers, but I think that was a different forum. Several did it and I remember a couple used liquid nails to hold the tiles on, and just butted them tight so no grout.
If I was going to add some, I think I'd use liquid nails and then a good caulk, maybe even a grout looking caulking, flee the joints and seams
Sent by me
Joel and Teresa
2016 Sabre 34TBOK
2006 GMC 3500 CC LB DRW 4X4