You misunderstand the purpose of relationships. Having a relationship
defined between tables does not automagically add new records to the
"child" tables; instead, it PREVENTS you from adding a record which
would be an "orphan". There is no need and no benefit to creating
empty "placeholder" records in the child tables. Typically you would
use a Form based on the "one" side table, and one or more Subforms
based on the "many" table(s); when you enter a record on the subform
it will automatically fill in the Master Link Field into the subform's
Child Link Field, creating the link when you add data (but not
before).

The Linked Table Manager is a totally separate issue; it's not for
maintaining relationships, it's used when you have the Tables in one
database and the Forms, Queries, and so on in a different database.
This technique is very commonly used for multiuser databases; everyone
gets a copy of the "frontend", all linked to the shared "backend". But
again, this has no direct bearing on the relationships!

                 John W. Vinson[MVP]

Adding records in one table should not generally add records into another
table. For instance, if you add an Order record in the Order table in
Northwind, it doesn't automatically add a record to the OrderDetails table.