For security reasons, you probably shouldn’t.
It’s difficult to use a computer or tablet for general purposes without leaving personal data behind on the device. It’s especially risky to set it up with your personal passwords for email or other accounts.
With that said, it is your own tablet, and if you are aware of the risk and prepared to secure it yourself, you can customize it however you like.
Since Ocean Tablet runs on the stock Android system, you can browse Google’s Android support sites for more information.