Con el código siguiente se pueden listar las tablas de la base de datos con el peso de cada una en un servidor Microsoft Sql Server:
SELECT
t.NAME AS Tabla,
s.Name AS Esquema,
p.rows AS NumeroDeFilas,
CAST(ROUND(((SUM(a.total_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS TotalEspacio_MB,
CAST(ROUND(((SUM(a.used_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS EspacioUtilizado_MB,
CAST(ROUND(((SUM(a.total_pages) - SUM(a.used_pages)) * 8) / 1024.00, 2) AS NUMERIC(36, 2)) AS EspacioNoUtilizado_MB
FROM
sys.tables t
INNER JOIN sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN sys.allocation_units a ON p.partition_id = a.container_id
LEFT OUTER JOIN sys.schemas s ON t.schema_id = s.schema_id
GROUP BY t.Name, s.Name, p.Rows
ORDER BY TotalEspacio_MB desc
Tambien dejo una manera simple de listar las bases de datos completas:
SELECT d.name,
ROUND(SUM(mf.size) * 8 / 1024, 0) Size_MBs
FROM sys.master_files mf
INNER JOIN sys.databases d ON d.database_id = mf.database_id
WHERE d.database_id > 4 -- Skip system databases
GROUP BY d.name
ORDER BY Size_MBs DESC