Fields can be associated with any of the available lookup tables. When a field is associated to a Lookup Table, the values for the field is selected from the values available in the lookup table.
By default only fields with string values are listed when associating a field with a lookup table. When you enable the Show Numeric Fields option, fields with numeric values will be included in the list of fields to choose from.
To associate a lookup table to a field, select a table from the list which is available in the Lookup Table field: