List Data Size for SQL Tables

DECLARE @TableSchema VARCHAR(128)
DECLARE @TableName VARCHAR(128)
DECLARE @TableFullName VARCHAR(256)

-- declare a cursor to get all user table names
DECLARE t_csr CURSOR
FOR 
SELECT TABLE_SCHEMA, TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
FOR READ ONLY

-- a temp table to store the results
CREATE TABLE #TMP
(
 SchemaName varchar(128),
 TableName varchar(128), 
 RecordCount int,
 ReservedSize varchar(50),
 DataSize varchar(50),
 IndexSize varchar(50),
 UnusedSize varchar(50)
)

DECLARE @MTMP TABLE 
(
 TableFullName varchar(256),
 RecordCount int,
 ReservedSize varchar(50),
 DataSize varchar(50),
 IndexSize varchar(50),
 UnusedSize varchar(50)
)

-- open the cursor
OPEN t_csr

-- get the first table name from the cursor
FETCH NEXT FROM t_csr INTO @TableSchema, @TableName

-- loop until the cursor was not able to fetch
WHILE (@@Fetch_Status >= 0)
BEGIN
    SET @TableFullName = @TableSchema + '.' + @TableName
    -- dump the results of the sp_spaceused query to the temp table
    INSERT @MTMP
        EXEC sp_spaceused @TableFullName
	  
		INSERT #TMP
		SELECT @TableSchema, 
		TableFullName,
		RecordCount,
		ReservedSize,
		DataSize,
		IndexSize,
		UnusedSize
		FROM @MTMP

		DELETE FROM @MTMP
		
    -- get the next table name
    FETCH NEXT FROM t_csr INTO @TableSchema, @TableName
END

-- dispose the cursor
CLOSE t_csr
DEALLOCATE t_csr

-- return the stored results by table DataSize
SELECT * 
FROM #TMP
ORDER BY CAST(LEFT(DataSize,LEN(DataSize)-3) AS NUMERIC(18,0)) DESC 

-- clean up
DROP TABLE #TMP