The two columns are applicants that were offered a seat (people who already interviewed) and applicants that were denied seats out of the total people that applied.
Since the schools run on rolling admissions, and there’s lots of movement in the cycle, the offered seats is always much higher than the amount of people that accept those offers. Usually they only give you a couple weeks to respond to an acceptance offer before they offer it to other people.
For ex: A school might offer 300 acceptances throughout the entire cycle, however only less than half will respond or take that acceptance. So even though they offer 300 different people an acceptance, they only end up with say 120 in the entering class. People might choose other schools based on location, cost, needs, other factors. Throughout the cycle the schools hand out acceptances methodically based on how much space they have left and how many deposits were paid.