If you have the Isotherm Cruise 130, it draws an average of 400 watts per day, or 16.7 watts per hour, if what I have read is correct. Your 260AH batteries have 3,120 watt in them which will run this fridge for 7.8 days from 100% charge to 0%. Of course they would shut off before that to protect themselves.
Your 240 watts of solar should produce 900 to 1500 watt-hours per day assuming it is sunny, and they are clean, which should allow you to run this fridge indefinitely by itself. You should probably look at other electrical items you are using.