Hi Dhiraj,
Most of the SAP Tables have the field named as 'objType'. You can find the object type there for a particular document or master data.
Also you can check the following links:
SAP Business One Form Types and Object Types
How to check the object type in OPRJ table in SAP Business One?
list of object type for sp_transactionnotification
How to know Object Type or Trans Type..?
Hope it helps.
Thanks & Regards
Ankit Chauhan