It depends on the relationships.
If the relationships are one to one--any given record matches at most to just one record in the other two tables, then you can put the fields from all three tables on the same layout.
But relationships that match records by name are not ideal. Names are not unique, subject to spelling variations (one person might enter my name as Phil and another might enter it as Phillip...) and also vulnerable to data entry errors.
Thus, you'll need to be careful of records that do not match that should and some that match that should not.