Hi Niranjan,
Try setting the history session to desired point and delete the history
set history session UTCTIMESTAMP or COMMIT ID
delete history from <schema>.<table>
Ref:
Set history session:
https://help.sap.com/saphelp_hanaplatform/helpdata/en/20/fd261a751910149253bd03d73f520d/content.htm
SQL DELETE:
HTH
Gopal