If I want to use a survey for clients to select times from a list for a webinar, is there a way to use the time they picked and have a hold placed in their outlook calendar after the complete the survey? So if for example I picked from a long list of times 8:30 AM EST, once I finish the survey I would get the calendar invitation to save in Outlook on it’s own?

Not sure about microsoft outlook but you can use google calendar task to send the calendar invitation.

Using a survey item response to create a calendar event in Outlook

Using a survey item response to create a calendar event in Outlook | Experience Community