I use an ical subscription link to bring in a table’s calendar into my outlook, but to do that for all my tables in all my bases in my workspace isn’t practical as each ical link creates a separate calendar in Outlook.
I can’t help with combining all calendars in a workspace — which, for those of us with roughly 300 bases in a single workspace, may not be so workable a solution — but if your work flow supports combining bringing multiple calendar-containing tables together into a single base, the approach described and demoed here might help in consolidating them into a single iCal link…
There are lots of people out there asking for this (me included), but not much reply/support from developers. See also this post Help creating a master calendar for a base?