Custom bookings for open day

We have just set up a basic page for Microsoft bookings but I am struggling to set it up for our particular requirements. I have gone round in circles a bit so any help would be very much appreciated. Basically, we have an open day of our facility in April and I want to set up a series of days where people can book. From Tuesday to Friday, we'll have 8 slots per day. There will 4 slots available from 10:00 am - 12:30 with four staff being available and then 4 slots in the afternoon from 1:00 pm - 3:00 pm So 4 separate people can be given a tour at the same time (10:00 am) or within 10-15 mins of each other by 4 different staff. So I don't necessarily need set times every 30 mins or every hour. So ideally we'll have two start times - one at 10:00 am and one at 1:00 pm and we can take 4 people in the morning and 4 people in the afternoon. I have looked at the system and I can see you can assign staff etc but I cannot overlap the times or create 4 for the same starting time. Is there a simple way to do this? Many thanks for your help.