That scene was rather discomforting to even think about.
Once the elaborate series of ceremonial rituals were complete, the examination officially began. Officials from the Ministry of Rites distributed test papers to each scholar. The Ministry of Rites Minister, the Honglu Temple Minister, and four Grand Secretaries from the cabinet were seated on the benches on either side of the examination site, while a table and chairs intended for the emperor were positioned in the center.
Besides these few proctoring officials, the Imperial Guards and the duty eunuchs were also present. Although there were no separate examination rooms, cheating would have been extremely difficult under so many watchful eyes.
Moreover, the Palace Examination was unlike scripture-based tests; cheating wouldn't have made much sense.