I added this 120 volt receptacle in the dinette bench next to the kitchen counter. I installed a new Marinco 120V 15A inlet on the side of the trailer near the other hookups. Since I was installing new laminate flooring, I made up a 2 1/2" high (and 3/4" thick) baseboard to run between the dinette benches from one side of the trailer to the other. I cut a groove in the rear of it to hide and protect the 120V cable (Romex in the US?). Didn't have to run power wiring under the floor or through the ceiling.
Now we can run a rice cooker, coffee pot, toaster or any other appliance up to 1500W while all the other stuff is running in the TT.