auto create record in table B same as Table A

[HHC]

Hi,
how to create automatically create same numbers of record in child table when parent table created. So both fields look same.

Please help....

[comment]

Why would you want/need to do such thing? It goes against the very idea of a relational database.

[HHC]

Table A is list of services with details and Table B is each service markup %. for client.
 With auto recreate full list so i know which service i missed to set markup %.

[comment]

Sorry, I don't follow. Please don't be laconic when asking for help.