Hm, if you paste comma separated values into a linked field that counts as multiple links.  Check out this extension for it too 

For the forms I’m afraid one by one’s the only way to handle it.  You could potentially try pasting text into a text field and using a script to parse it and link to the right records, but that seems very overengineered

Hi ​@Nico Larreta,

You may want to check out Fillout’s advanced forms for Airtable.

Fillout lets you simultaneously select multiple linked records when adding linked records via a form.

Fillout is 100% free, and it also offers hundreds of features that Airtable’s native forms don’t offer, including the ability to update Airtable records using a form, display Airtable lookup fields on forms, perform math or other live calculations on your forms, accept payments on forms, and much more.

I show how to use a few of the advanced features of Fillout on these 2 Airtable podcast episodes:

• Using Fillout to create an eSignature approval process with PDF file creation.
• Using Fillout to create an order entry form with line items.

Hope this helps!

If you’d like to hire the best Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld

You’re the gift that keeps on giving  Thankyou

There are many ways to do that.
You should understand that each link in linked field exists in both tables.
To establish ‘one-to-many’ relation, it is better to act from ‘many side’
For example, when you can filter/group records which you have to link, just link one and then copy-paste link to others.
Also, link tied to exact record, by record ID. 
So, if you have, for example unique User ID in the middle of both tables, you can temporary shift this ID in the primary field, switch to other table, use ID for link (just paste column of IDs to the linked field), then return the primary field back. Links will stay, just their ‘name’ will change.

 

That’s how it works.