Can I use my cell phone's internet connection as a VPN? I'm still learning about VPNs so forgive me if this sounds horribly mistaken, but if I understand it correctly a VPN is an encrypted internet connection between two computers that can also be used as proxy. My question is: supposing I am ON MY LAPTOP at a library/work/school and the WiFi has a filter that prevents access to some websites, in theory would I be able use the unfiltered 4G data connection from my Android tablet or phone to gain access to those sites remotely? 

I know I could just tether the device and use the connection that way but I'm curious if it'd possible to use the data plan on the tablet that I leave at home (it has perfect 4G data service there) that way, should I ever need to use an encrypted connection to get around some web filters, I could always have that available to me. I currently don't have a home computer that I can leave running all day, otherwise I'd run something like Hamachi. 

Thanks for reading and sorry if this is a noobish question!
You can use VPN applications to access restricted websites on any android tablet/phone.
Here are a few of them 
Flash VPN
Hot spot shield

But i think you will not get exact 4G speeds while using VPN.