This is all subjective on the draw that these devices have.
TV's are power hungry pigs (relatively). I agree with Irving on using the tablets/phones for watching a movie while camping.
You also have to consider the losses incurred by running an inverter to create 120VAC to run your TV, DVD Player, Etc.
Charging phones and tablets during the day, when you are likely to have an excess of solar, is a great plan.
The size of your system depends on the space and weight you are willing to put into it, and the power that you need to use.
Your CPAP Machine should have a current spec on it's power supply (look for input voltage and current ratings on it - something like 120-240VAC @ .5A (random numbers)). Figure out how much power that wants, add in charging 2-4 phones at ~3AH/ea, 2-4 tablets at ~6AH/ea and you can start to build a power budget, and then spec your batteries and your panels to support your wants.
Once you get all that started you also need to think about if you want to be able to go a day or two without any usable sun (camped in the shade of trees, cloudy rainy weather, etc), and then you get into scaling your batteries and solar for surviving multiple days and how long does it take to recover when you do get back to sun?