I would not recommend the 8 GB version for your parents.
The device is easy to use. However, the version of Android that it comes with really wants to install all the apps in main storage. Even if you put a 32 GB card in it, the apps are all going to get stored in the 8 GB that came with the device. If your parents aren't the least bit technical, if they find apps that they like they will easily fill the 8 GB, which will eventually get very frustrating for them.
I recommend you get a tablet that has a minimum of 16 GB, or comes with Android Marshmallow (which allows for installation on external media). I rooted my tablet to handle this drawback (and even then it's a pain as the Galaxy Tab 4 doesn't keep the settings through power cycles and I have to keep it charged or put the icons back on the desktop all the time).