Refer to the tablet's User Guide/Manual if you have a physical copy.
If not, go online to the manufacturer's website, to learn about when and how the tablet should be properly charged.
For the most part, I would expect that the tablet is simply plugged in and allowed to fully charge to 100%. Should fully charge in some given amount of time per the documentation. Failure to charge to 100%, stay charged, take lots of time to charge, or even get hot indicates a problem somewhere.
However, charging can be problematic and I never leave a new device unattended during the first few times it is being recharged.
Batteries can get quite hot (especially there is a defect somewhere in the charging process) and the heat can cause...