Add new entry to multiple associated tables in one screen

I’ve got multiple collections/tables that are associated/linked with each other: Hostnames, IPAdresses, MACadresses.
Now I want to enter a new host with a new mac address and enter a new IP-Address, so I want to add something to all three collections/tables in one go. I didn’t understand from the docs how to go about this - is it at all possible?

Thank you

Create association fields for them, and then you can add these fields in the same form and use sub-tables, sub-forms, and other appropriate components.

I had the exact same issue for the last 2 week up till 15 minutes ago. I have been changing the input fields and getting varied resuIts. When I read the support response and decided to ‘rebuild’ the entire input page and low and behold, IT WORKED. So if I input from the old page with the updated association fields, the associations are not appearing in the table. But when I input from the new page, all the associated fields are filled with data.