Rediff does not put any restriction on the number of tables that you can create in a database. However, you will need to MySql and MS SQL documentation (depending on the database that you use).

For user of the Plesk Control panel, total size of the database cannot exceed 50% of the total space purchased.

For Ensim control panel users, the size of a database is restricted to 20 MB irrespective of the web space purchased.