A piece of baseboard
hillbilly cord protector
It’s a power strip. They’re handy because it allows you to plug in multiple things into one wall. Be careful not to overload it with space heaters, air fryers, etc.
Jk I have no idea what that board is
Unscrew it and see what wires it’s hiding. You can decide from there if you can make it look better.
Maybe to set the couch away from the wall?
Either a baseboard to cover “cabling and tubing” or it was intentionally placed there as a space for the couch spacing from the wall. Our Casita had those running down one side of the RV and under it was all the wiring and plumbing and propane line.
It probably protects some wiring that goes from the wall into the floor