Where G-Tab fits
G-Tab competes at the bottom of the tablet market against Blackview and the cheapest models from the larger brands. You are buying screen size and basic Android for the lowest price that still gets you a working device.
For a second screen for video, a reading tablet, or a first tablet for a child, that is a sensible purchase. For anything demanding - heavy multitasking, drawing apps, games - the money is better spent one tier up.
The 4G models take a SIM, which makes them useful as a travel or car tablet without tethering. The Wi-Fi models do not, and the two look identical in photographs.