Tablets don't have/need ventilation in common circumstances. While ACTIVELY using WiFi and watching videos can cause your tablet to heat up because of the heightened use of the processor and radios (especially heavy browsing is known to cause some heat), it shouldn't be unbearable. And if it happens with WiFi off or with WiFi on but just during standby, there might be something wrong with the tablet or a rogue app that's just consuming too many resources.
The tablet, however, is protected, and if it reaches a point where the heat might damage the internal components, it automatically shuts off.
Personally I have this tablet and it doesn't get hot. It gets warm when browsing and streaming videos, but nothing that would make me jump or not want to touch it.