Используйте вставку в новый стол, такой как этот
alter PROCEDURE [dbo].[sp.StoreBilling]
AS
BEGIN
SET NOCOUNT ON;
DECLARE @Stock decimal(10,2)=0.00
DECLARE @Spoilage decimal(10,2)=0.00
INSERT INTO NewTabeName(Stock, Spoilage, StockChange)
SELECT A.Stock, A.Spoilage, A.Stock-A.Spoilage AS Inventory
FROM dbo.Store AS A
END