The Price list grid in the “Set Prices” window has a list of rooms. Clicking on each of these rooms opens the room editing window in the Price list. It allows you to edit some of the settings for the Airbnb listing and Booking.com rate plans that are linked to your room. These settings apply to your individual "Commission and Availability", Airbnb's "Price per extra guest", and Booking.com's "Occupancy-based pricing rules".
If you can't open the room edit window in the Price list, it means that the room is not connected to either Airbnb or Booking.com.
If you cannot edit the individual "Commission and Availability" settings because it is labeled "Enabled" and has inactive fields for setting the commission amount, it means that you have global "Commission and Availability" enabled in a given sales channel. If you want to have more flexibility in setting commissions by using individual "Commission and Availability", you must first disable the global "Commission and Availability", which is described in the article How to set global “Commission and Availability”?.
Please remember that the above information applies to the room edit window in the Price list. If you need to edit room information, e.g. room name, capacity or address, open the room edit window in the booking calendar.