Thank you for reaching out.
On des_dr2, we'll add it to the xmatch web tool this week still.
On des_dr1, the main table is .main (not .object), and if I select it, it does load the columns (and also pre-loads 'ra' and 'dec' columns). If you do still see that no columns are loaded, could you please email maybe a screenshot or two to datalab@noao.edu ? Thank you!