Linking to another table : an error has occurred - you've exceeded the usage limits for this base

Hi all,

I’m trying to link entries from one table to the primary key on another table and am getting this error message:
“An error has occurred. You’ve exceed the usage limits for this base.”

The table (products) with the primary key I’m linking to has 423 records and the table (purchases of products) being linked as just 75 records.

I’m on a pro plan trial and am not aware on any limitations related to linking entries between tables. I’ve been unable to find any help on this topic so any help would be great.