Not sure what you mean with “ when I fill in that field from Table B (call it Calc1) …”
You can put the calc fields from Table B on a layout of Table A, and you can even enter them, but since you can't write into a calculation field,
there is no trigger for FM to create a new related record. You can control the creation of a new related record via a triggered script, or, in order to
emulate the described behaviour, create a dummy non-calc field and write something in it (You could even use the foreign key field for that purpose, but then I'd recommend using a script trigger to disallow field entry once it is non-empty.)
Yeah. That is what I meant by "when I fill in that field" (if it were a text field I don't have this problem, but because it is a calc field, there is nothing triggering FM to create the new record.
How would you go about creating the new record via a triggered script?
Obviously, I don't know your solution, but you write that the three calc fields in TableB are based on a certain field (Field1) in TableA. So I guess you need the related record as soon as there is a value in Field1.
You could write a trigger script which checks OnObjectExit of Field1 if there is a value in it - and if there isn't already a related record! - and if so, grabs the pk, goes to TableB, creates a new record, sets the fk, commits and returns.
Analogous method for any other logic that may apply. Don't know if this is the best or “official” method, but it works.