I don't know if a specific feature deals with this, you would generally handle this via schema's. It is usually bad form to have applications running or connecting as table owner (ie in the schema in which the table was created). Instead create another schema with insert only priviledges to the table.
grant insert on tableowner.tablename to tableinserter;
This way applications connecting as 'tableinserter' have no rights to update/delete on the table.
For additional security you can create a before update or delete trigger on the original table which just raises an exception.