The battery is rated at 100Ah which is the rating you want to use for house batteries. So 200Ah total in parallel. Best to limit the drain to 50% or 100Ah.
You didn't specify 2A AC or DC for the TV. Assuming AC then the inverter would draw 20A+ and your run time is 100Ah/20A = 5 hr. If DC then it's 50 hr. That's for a 100% charged battery.
However RVs have other drains like refer, smoke detector, lights etc.
Plus I would not use a battery rated for both starting and house. Instead I'd use 2 6V deep cycle batteries in series. Typically they are about 220Ah but designed for more cycling.
