Thank you for the reference. In my case I was using an Oracle DB. What a developer suggested was that, in the Oracle DB the ID's are automatically set to autoincrement hence, we need not pass the ID parameter. In the Demo app, the steps i followed in Outsystems were:
-> i created a new structure for the columns of the entity
->then appended all excel values to the structure
-> finally i passed the structure to the BulkInsert Server Action.
Note: I referred to the first link and made some changes to the Bulk Insert code, mentioned in the post.