Who needs a tablet with a 3G/4G connectivity? All you need is a WiFi.
People who owns a tablet, owns a smartphone. Why would you need a 3G/4G connectivity on you tablet? That will just be a waste of money. Why?
Regardless of your provider or plan, if you have 3G/4G tablet in addition to your smartphone, you have two accounts or bills you need to pay if you are on post paid or recharge if you are on prepaid. That will be double your expense. You will not be able to use internet on both devices at the same time anyway.
Why not just have a smartphone, then a if you want to buy a tablet if you already don't have one, go for the WiFi version. you don't need more than that. Buying a 3G/4G tablet is an overkill, a marketing ploy of the manufacturer and just a waste of money. If you already bought a 3G/4G tablet but do not want to use the feature, you still wasted your money in paying for something you do not need.
If you want to connect to the internet using your tablet when no hotspots around, tether your smartphone to share connectivity with your tablet. That's all you need.