Philanthropic gift categories are currently defined by NOZA and table values come over directly from the NOZA source. The table is not accessible to clients for making additions.
I recommend shops be able to add their own categories, while leaving the NOZA categories intact for WealthPoint imports. Sometimes an organization wants to have more refined categories that are specific the organization's focus than what NOZA provides for reporting and prospecting purposes. This is especially true for foundations, where the much more specific Foundation Center categories are particularly useful. Additionally, not everyone uses WealthPoint/NOZA and may want to use categories from WealthEngine or even the Foundation Center to facilitate data imports from those vendors.