Memory usages per table, index with free space etc. ( per database)

SELECT
obj.[name],
i.[name],
i.[type_desc],
count(*)AS Buffered_Page_Count ,
count(*) * 8192 / (1024 * 1024) as Buffer_MB,
avg(free_space_in_bytes)as' Avg bytes free per page',
obj.index_id
FROM sys.dm_os_buffer_descriptors AS bd
INNER JOIN
(
SELECT object_name(object_id) AS name
,index_id ,allocation_unit_id, object_id
FROM sys.allocation_units AS au
INNER JOIN sys.partitions AS p
ON au.container_id = p.hobt_id
AND (au.type = 1 OR au.type = 3)
UNION ALL
SELECT object_name(object_id) AS name
,index_id, allocation_unit_id, object_id
FROM sys.allocation_units AS au
INNER JOIN sys.partitions AS p
ON au.container_id = p.hobt_id
AND au.type = 2
) AS obj
ON bd.allocation_unit_id = obj.allocation_unit_id
LEFT JOIN sys.indexes i on i.object_id = obj.object_id AND i.index_id = obj.index_id
WHERE database_id = db_id()
GROUP BY obj.name, obj.index_id , i.[name],i.[type_desc]
ORDER BY Buffered_Page_Count DESC