Link to Multiple Records PLUS a separate column showing the unlinked records

Why do you want that? What is your use case?

The closest I can think is to have a View filtered in your table B, viewing only the records that are not linked (field empty).

I was just about to offer a suggested approach — but slammed to a halt when I noticed your phrase,

I clearly don’t understand what you are doing — let alone what else you wish to do. Would it be possible to provide a link to the base?

Thanks, that’s a simple and creative solution that I was overlooking. I’m working on a object/component inventory for a large app. I have one table that lists all of the objects we’ve found. As we inventory portions of the app in another table, we link to the objects used to create that page/section.
The thought is, that we’d also like to see the objects that are repeatably not being used… so that we can get rid of any components that are ad hoc.

To add to Elias’ suggestion, you could also create a formula that flags records IF they are blank/un-linked as well - then you would be able to see all records in one view - depending on what you need to achieve.

Pulling the ‘un-linked’ records to your second table is the challenge. But I think this would be possible using a third table that aggregates (rolls up) the un-linked records. This third table would use what I consider to be @W_Vann_Hall’s patented technique of basically creating a single record in this ‘third’ table which is linked to ALL records of both of your existing tables (this is where the small bit of extra work comes in). This would essentially enable you to create an array of the un-linked records from, let’s say, “Table 1” ; pull them to the new “Table 3” ; and look them up back in “Table 2” – where you wanted the data to begin with. Bit of a long workaround but I think it’s possible, just not elegant.