When you first open Pinnacle, it will pre-load data from some lookup tables into your computer's memory. The lookup tables that are most commonly used are the tables that will be pre-loaded. This data caching will speed up Pinnacle when viewing frequently accessed lookup tables.
If you want to refresh the data cache, you can select the Refresh Data menu option from the File menu in any module. This will reload tables into the data cache, and will include any information in the tables that might have been added since the last time the table was loaded.