In Power Pages, we can go to Setup tab in the Design Studio to configure the data security by creating permissions and web roles for the table by providing the below highlighted values.
Access Types: Which level of access to be given for the selected Table.
Permission: What kind of permission needed for the user on the selected Table, should be selected here.
Roles: The users under the selected web roles will gain the permission selected for the Table.
Anonymous Users: When you set this it doesn’t require any authentication for the user to see this table content in Portal.
Authenticated Users: When you set this it requires users to be authenticated before seeing the table content in Portal.
Administrators: This role gives the user complete access to the table content in Portal, but still the user should be authenticated.
When the user is assigned to any of these web roles, automatically he will gain access to the predefined set of tables in the Portal.