The Singleton table type contains system or functional application control information, often referred to as Setup. There is one Setup table per functional application area, for example, one for Sales & Receivables, one for Purchases & Payables, one for General Ledger, one for Inventory, and so on. Setup tables contain only a single record. Since a Setup table has only one record, it can have a primary key field that has no value assigned (this is how all the standard NAV Setup tables are designed). The Singleton table design pattern can be found at http://blogs.msdn.com/b/nav/archive/2013/07/19/nav-design-pattern-of-the-week-single-record-setup-table.aspx.

The Inventory Setup page is as follows: