Airtable today supports the linking of one table to another via a field, but that field must be populated either by:
Having the user key/select the appropriate value in the linked field
Using a manual process to occasionally populate data (i.e. copy/paste)
Using a 3rd party service like Zapier or Integromat to listen for record changes and populate the value
Option 1 works, but can be annoyingly inefficient from a data entry perspective.
Option 2 is too kludgy and isn’t practical for anything beyond a 1 time data population.
Option 3 adds complexity and the need to learn/bring in another system.
Ideally, there’d be a way to auto-populate the Linked Field using a formula. The linking would either find a correlated record in the linked table, or if none found, then create a new record.