Hi Dharm,
How did you apply the data and log backups from once source system to another?
Which backups are you using? Filesystem or BACKINT?
why do you think the new Database is much larger compared to source system? is it just the data volume size?
Can you execute refer to SAP note 1969700 and execute the scripts HANA_tables_ColumnStore_Overview and HANA_Rowstore_Overview scripts on both source and destination HANA Database's to compare the size and determine which one of them is causing the increased size on destination system?
Secondly you can also check if row store tables need reorganization due to large free space using the below SAP note, please do not implement the OFFLINE or ONLINE Reorganization unless your landscape meets the pre requisites
http://service.sap.com/sap/support/notes/1813245
Let us know your findings
Sunil