If a label was assigned to the Site Custom Fields Table 1, 2 or 3 field, you will then enter the choices in the corresponding table. For each choice you would like the User to be able to select from, create one record in the corresponding setup table. The number of records you may enter is unlimited.
The entries in the example Custom Fields Table 1 below are the choices that will be available in a drop down menu in the Site Information record, on the tab labeled Custom Fields.