To confirm whether you are able to access the custom global table via the scoped app or not. You can follow the below steps.

1. Navigate to background-scripts and execute the below script.

var gr = new GlideRecord('u_user_access_list');
gr.addQuery('u_user', 'bdb4e9601341b2006bda75c36144b062');
gr.addQuery('active', true);
gr.query();
while(gr.next())
{

gs.info(gr.getRowCount());

}

NOTE: Make sure to select the correct scope before triggering this script.

Thanks,

Pradeep Sharma