I can answer your first question only, the second one seem unfinished.
A tablet (in this context) is a small computer with a big touch screen, a camera and a microphone built in that needs no keyboard or mouse to function. Or you can say that a tablet is big mobile phone, that can't phone or text, but can do everything else a smartphone like your wife's SM-210 can do, with a bigger screen.
Tablets come in three variants: with Windows as OS (there are very few of those), the iTab's from Apple with iOS as OS (big iPhones that can't phone) or with Android as OS (big smartphones that can't phone). So an Android tablet is the commonly used kind of tablet (more than 80% of them run Android, the remainder is an iPad).
Just like PC's come in 2 variants: with Windows or with Linux. And cars come in four variants: electric, hybrid, gas or diesel. But with PC's you can switch between those, and with tablets and phones and cars you can't.
My wife currently owns a Samsung SM-T210 which she knows little about regarding its operating capabilities but then neither do I in that I stick to my desktop computer. My wife returned from a visit to our daughter Saturday voicing praise for the Samsung 10-1 which our son-in-law had just bought for our daughter. I asked her on what basis my wife made her judgment a question to which she replied with abuse such as, "watch it mate or you will be getting your own dinner."
I suspect that her impressions were gained by just looking at the device which to be fair is attractive. I will come clean and own up to not even understanding the difference if difference there is between a "Tablet" and an "Android Tablet" so I thought I would ask that question here in an attempt to start accumulating sufficient knowledge to make a qualified judgement regarding a replacement for the Samsung SM-T210Tablet she now distains. I suspect that it may come down to screen size.
The primary reason my wife is interested in a replacement Tablet is because of her love for our new grandchildren and her wish to record them to show anyone who she can capture. She also uses it to text our children which I suspect just scratches the surface of a Table's capability.
Anyway, I would like to help her and if possible lead her in a direction where she can send Emails and do the normal tasks one does with a desktop computer such as clear the rubbish away. As you can see, I am very much lacking in the technical knowledge department and I would like to learn.
So to start my quest for information,
1. "What is the difference if difference there is between a "Tablet" and an "Android Tablet"
2. "How does the Samsung
If this is the wrong forum could someone please move it to where it should reside.