To add a new table to your shared view, click the "Add" button found in the tables section of the configuration page.
If the table you want to add to your shared view has never been used in a shared view before, it will not show up in the list of tables when clicking the "Add" button. In that case, you'll need to do the following:
Add a new linked record field to any tables you want to add to a shared view. The field needs to link to the miniExtensions table in your base. The miniExtensions table may be called either "miniExtensions", or "miniExtensions - DO NOT EDIT".
Once the linked record field is created, go back to miniExtensions and click the "Refresh tables" button in the "Add" menu. The new table(s) should show up within a few seconds.
Optional, but recommended: Hide the linked record field pointing to the miniExtensions table. You won't need to do anything with this field, so it's best to keep it out of sight to prevent any accidental changes. Changing or removing this field while still using this table in a shared view would break that shared view.