Individuals are automatically added to your personal beneficiary table/report when you pay them or if they register via your branded signup. If they are not on the list for some reason you can search and add them to your beneficiary table. This is useful for reporting purposes.
If you would rather add them separately then you can goto the 'Beneficiaries' option
1) Click on 'Beneficiaries' in the left menu
2) Search and add any user beneficaies