CREATE TABLE #temp 
       ( 
       [name] nvarchar(128),
       [rows] char(11),
       [reserved] varchar(18), 
       [data] varchar(18), 
       [index_size] varchar(18), 
       [unused] varchar(18) 
       ) 

INSERT INTO #temp 
EXEC sp_MSforeachtable @command1="EXEC sp_spaceused '?' "

SELECT
       [name] AS TableName,
       CAST([rows] AS int) AS NumOfRows,
       CAST(REPLACE([reserved],' KB','') AS int) AS [TotalKB]
FROM 
       #temp
ORDER BY 3 DESC

SELECT SUM(CAST(REPLACE([reserved],' KB','') AS int)) AS TotalKB_data FROM #temp

DROP TABLE #temp