On our coach as well as many others I've noticed, the front TV and components are on the same circuit as the streetside outlets, and our wiring diagrams bear that out. Our 2006 model has breakers with built-in GFCI's, but older rigs use standard GFCI outlets, one per circuit, especially if at least one outlet is in a location subject to moisture. Your circuit in question may not have an outlet like that although the dining table could be considered one as your accident exemplifies, but since ours for example has the fridge's icemaker on that circuit and is the one outlet located outside behind the fridge, the circuit is GCFI protected on its breaker.
Whether or not your circuit has an at-risk outlet, it may still have a GCFI outlet somewhere regardless. So I'd check every outlet down the streetside and up front, including any in outside bays or the outside fridge access and any at foot level around the front console near the driver, for a GFCI outlet that may need resetting.
As to the device in your photo, I have no clue and leave that to others to decipher. It may be the ignition cutout safety switch, so the TV (and its motor mount apparently) cannot be used, via inverter or genset, when the coach is on the road.
Joel