要查看SQL Server中所有表的大小，可以使用以下查询语句：

SELECT t.NAME AS TableName,s.NAME AS SchemaName,p.rows AS RowCounts,SUM(a.total_pages) * 8 AS TotalSizeKB 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 TotalSizeKB DESC;

这将返回一个包含所有表的名称、模式、行数和大小（以KB为单位）的结果集。