Use the AfterInsert event procedure of the form where entries are made into
one table to Execute an append query statement so a record is also added to
the related table. (You will need some understanding of VBA and SQL to
achieve this.)
Whether this is the best solution depends why you need to do this. If you
have split the fields across 2 tables because you could not fit them all
into one table, the table design is wrong. You need to create related tables
with many records, instead of one wide table with many fields. (That may not
be what you are doing, but it is a very common mistake.)
