Question on calendar and ICS file I receive emails with ICS files. 

When I double click on them, the event is created successfully in my calendar but many times it chooses things like "family room" as the calendar.

I don't want this. I have integrated google calendar into my calendar and I want that everytime I double click an ics file the event is always created in my google calendar which is integrated into my calendar application.

does this question make sense? is it possible?

I don't even know what is "family room" and why do events go there.
On your Mac, if you open Calendar>Preferences>General at the bottom there is an option to change your default calendar.

If you have Family Sharing turned on through your iCloud account, your shared family calendar may be the default calendar.