Going to different layouts based on different tables is often a good and practical way to enter data. It's also possible to set up a variety of layout objects such as portals, tab controls and sets of global fields so that you can work with multiple tables on a single layout.
It all comes down to the structure of your data--how are the tables linked to each other in relationships and the various tasks you need to accomplish with your data.
Thanks Phil, but I already set everything up and it all comes up great. The portals and tabs do exactly what they are supposed to do. My problem is that when I want to input data that covers several different tables in the layout it just won't let me input anything.
I have an National Stock Number on one table. This Stock number has several different models so I have them on a separate table. By using the portals I can list all of the part numbers with each NSN, but when I try to enter them by adding a new record, it only lets me enter the information that the layout is based on, so I can't input a new NSN and Part Number at the same time.
You'll need to describe your set up and relationships in more detail. What you have described here should work and there are several different ways for adding new related records--including one option that simply requires entering data into the bottom blank row of your portal. That option requires the correct relationship details--including selecting "allow creation of records via this relationship" for the portal's table in this specific relationship.
I completely missed the allow creation of records. That was all that I was missing, and I had only missed it on one field.