Trigger in sql server management studio

I would like to create a Trigger in MSSMS (Sql Server) which, if I made an INSERT on a table A, with the last record of table B, it inserted 10 more records in table B, and so on every time I used the last one created another 10. But I do not know how to do the last record check, or last object in that table. Would anyone know how to do this?