Welcome to the community! Happy to have you here.
Each field (column) can only be linked to one table through a linked record field. When you create a linked record field you will be prompted to choose a table to link to. You can link to more than one record from the linked table, but not to different tables.
If you want to link to two separate tables you will need to create two separate linked record fields.
Let me know if that helps answer your question!