The following parameters are available :
Table
The table these permissions should apply to.

Username
The user to whom the permissions are granted. This user must already exist in the User Permissions table.

Hosts
The hosts that the user can access the table from.

Table permissions
The permissions granted to the user on all columns of the table.

Field permissions
The maximum permissions that can be granted to this user for any column of the table in the Field Permissions page.