The Inventory Report Entry Table
The source of the value in this field depends on the type of the inventory period entry.
If the type is Item, this field contains the sum of the values in the Cost Amount (Expected) field in the value entries for the item that this inventory report entry describes. This gives you the total of the inventory transactions that are not invoiced.
If the type is G/L Account, this field contains the sum of the values in the Amount field in the G/L entries for the inventory (interim) account that this inventory report entry describes.