Yes! It is possible to create group bookings and add multiple users to the same booking.
To do this, before confirming the booking, select 'Advanced Options'. Here you will find the drop down menu labelled 'Booking Participants'. From this drop down menu, you can select the users in the lab that you would like to invite to participate in your booking.
The users that you select to be added to the booking will receive an email invitation that they can then accept or decline.
You can see a list of invited users and their responses by selecting the booking from the calendar, and then selecting the Booking List tab
Group bookings are shown on the lab calendar in a light blue colour.