That generator is rated at 800W sustained output, so you'll probably find it most useful for charging your battery through the power converter/charger in your RV. It's not going to run a microwave or air conditioner, but could run a TV or other small electronics like a computer, though with that small engine and at that price point ($180), I'd be a little concerned about the power quality, so would probably just stick to using it to charge up the batteries.
If you had an 80 amp charger for your house batteries it might not be able to keep up with that, but with only 1 battery, you probably don't.
One thing to be aware of is that it's a 2 stroke, so burns oil+gas and will produce unpleasant exhaust that you'll probably not want very close to your RV (or your neighbors). Make sure you carry around some pre-mixed fuel for it, or at least carry a can of oil so you can mix it when you need it.