How To Free The Memory Occupied By Blob In MS Sql Server

i'm working in microsoft sql server and i got following problem:

I have a text files Asia.txt in E: folder with some data in it as shown below

Asia.txt

1, Mizuho, Fukushima, Tokyo
2, Minika, Pang, Taipei
3, Jen, Ambelang, India
4, Jiang, Hong, Shangai
5, Ada, Koo, HongKong

And I have a table Region, in the database Companies, as shown below.

1>CREATE TABLE REGION (ID INT,REGION VARCHAR(25),DATA varbinary(MAX))
2>GO

I queried all the data from Asia.txt, using the OPENROWSET function.

1>INSERT INTO REGION (ID, REGION, DATA)
2>SELECT 1 AS ID, 'ASIA' AS REGION,
3> * FROM OPENROWSET( BULK 'E:Asia.txt',SINGLE_BLOB)
4>AS MYTABLE
5>GO

it occupied some memory then i deleted this record using follwoing query

1>DELETE REGION
2>GO

then it deletes the record successfully but memory is not getting freed

can anyone help me out on this problem