Your readings are pretty much where they should be. The fluctuation is normal too.
My 2012 T12SC A frame has a drain of about 0.3 amp. Like you, I see fluctuating values. You are measuring only a 30 milliamp (0.03 amp) fluctuation, which is very small. That most likely is coming from your detectors. Some detectors don't draw a steady amount of current. They take samples periodically, and then go idle between samples to save battery power. Depending on how many detectors are sampling at any one time... 0.03 amp fluctuation is very reasonable.
The total current is normal too. Your coach may have more smoke/propane/CO detectors than my A frame, so a reading higher than mine would be expected. If your TV is 12 volt it will be drawing a small amount of current to be able to respond to the remote control. Clocks, antenna amplifiers, furnace/AC controls... anything electronic can potentially draw a tiny amount of power when it is "off".
You can look into a solar panel and charge controller to offset that parasitic draw and keep the battery from running down. 0.6 amp at 12 volts is 7.2 watts, assuming that the sun doesn't shine 24 hours a day where you are, a 30 or 40 watt panel would be enough to replace during the day what has been used at night.
It is also possible for water to get in and cause a small current to flow, particularly with any external electrical equipment. Not uncommon to see rain getting into outside lights, and it can bridge the contacts in the switch. Not enough current flows to light the light, but enough that your meter can measure it. Slide outs? Check the wiring for any damage that might allow water in.
2011 Grand Caravan