The first thing to point out is that Seats per Booking are OPTIONAL - you do not need to set up any seat types unless you plan to offer multiple seats per booking.
This would be used for tours or classes but not for individual appointments.
Seats/Booking can be used in conjunction with PayPal and the appropriate totals will be calculated, or it can be used merely to tell you how many customer of various type will be booking. ie: if you need to know how many adults vs children.
To disable the seats/booking capability, do not publish any seats types.
Publish: Sets one or more seat types to Unpublished. Only Published seat types will appear on the Appointment Booking screen.
Unpublish: Sets one or more seat types to Unpublished so they will not show in the Appointment Booking screen.
Remove: Deletes one or more seat types.
Edit: Opens the Seat Type Edit screen to allow you to view and modify the seat type.
New: Opens the New Seat Type Edit screen to allow you to add a new seat type.
Help: Opens this help screen.
ID: Unique ID for this seat type.
Seat Type: Seat Type name. This will become the booking screen label for the seat type.
Price: Price, per hour or per booking, for this seat type.
Group Pricing: Group Pricing allows you to define a fixed price for a group of up to x seats.
Order: Order the seat types will appear in the booking screen.
Published: Indicates the published state.
Click on the Seat Type to open the edit screen.