SQL - Way:

-- Use sys.tables, sys.indexes, sys.partitions, sys.allocation_units and sys.schemas to display the line number, and also the size of tables
select  sch.name as SchemaName,
        tab.name as TableName,
        par.rows as RowCounts,
        sum(alc.total_pages) * 8   as TotalSpace, 
        sum(alc.used_pages) * 8   as UsedSpace, 
        (sum(alc.total_pages) - sum(alc.used_pages)) * 8 as UnusedSpace
FROM       sys.tables tab
    INNER JOIN   sys.indexes ind 
        ON     tab.object_id = ind.object_id
    INNER JOIN   sys.partitions par 
        ON     ind.object_id = par.object_id 
            and ind.index_id = par.index_id
    INNER JOIN   sys.allocation_units alc 
        ON     par.partition_id = alc.container_id
    LEFT OUTER JOIN sys.schemas sch 
        ON     tab.schema_id = sch.schema_id
GROUP BY    tab.name, sch.name, par.rows
ORDER BY    UsedSpace desc