Tente este script - ele listará o número de linhas e o espaço usado pelas linhas de dados (e o espaço total usado) para todas as tabelas em seu banco de dados:
SELECT
t.NAME AS TableName,
i.name AS indexName,
SUM(p.rows) AS RowCounts,
SUM(a.total_pages) AS TotalPages,
SUM(a.used_pages) AS UsedPages,
SUM(a.data_pages) AS DataPages,
(SUM(a.total_pages) * 8) / 1024 AS TotalSpaceMB,
(SUM(a.used_pages) * 8) / 1024 AS UsedSpaceMB,
(SUM(a.data_pages) * 8) / 1024 AS DataSpaceMB
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
WHERE
t.NAME NOT LIKE 'dt%' AND
i.OBJECT_ID > 255 AND
i.index_id <= 1
GROUP BY
t.NAME, i.object_id, i.index_id, i.name
ORDER BY
OBJECT_NAME(i.object_id)
