Gary,

I don't think anyone can give a specific answer without more details of
the fields in the tables and the relationship between them.  But the
general concept here is that the only field(s) in both tables should be
the fields that define the relationship between the tables.  This is
typically the primary key field of the table on the "one" side of a
one-to-many relationship.  No other data should be stored separately in
both tables.  As for related data from the other table being displayed
on your forms and reports, this article may make sense...
http://accesstips.datamanagementsolutions.biz/lookup.htm