Final answer:
The requirement for an open buffet as part of the reservation is classified as a Delighter in the Kano model because it increases satisfaction when offered for free, but the lack of it does not cause dissatisfaction.
Step-by-step explanation:
The requirement to have an open buffet as part of the reservation would fall into the Kano category of Delighter. This is determined by the respondents' reactions indicating they are 'Satisfied' if a free buffet was offered, but their contentment does not significantly diminish when told the buffet is not free but available at a cost ($9.99), to which they responded 'Neither'. Delighters are features that, when provided, can greatly increase customer satisfaction, but their absence does not cause dissatisfaction because customers did not initially expect them as part of the service or product offering.