If an Account/Contact/Lead/Opportunity is already owned, you can assign meetings to the account owner automatically. You can create new queues in Assigned Meetings - Queues. If you have several queues created, the Assign to owner queue will always have priority over every other queue.
To set up this automation you can select the "Prioritize Routing Based On Ownership" Algorithm:
Add rules that apply to how you'd like to route based on ownership, for example:
If using Instant Booker, the Assignee is recognized based on the rules in the Ownership Queue automatically from the list of active assignees in the queue, as denoted by the green circle below next to Gaines:
If the booking is done by the prospect via a calendar link and the booking URL automatically recognizes the prospect (via an email or Salesforce ID), the calendar of the assignee is automatically shown to the prospect.