You can subscribe to your Full Slate calendar in Outlook. Please find instructions for that here.
To subscribe to your Outlook/Exchange calendar in Full Slate, you'll need to publish your Outlook/Exchange calendar using the icalendar (ICS) protocol. Please use the instructions under "Share a calendar by publishing it online" at http://office.microsoft.com/en-us/outlook-help/share-an-outlook-calendar-with-other-people-HA0103544... for this. Then, copy and paste the ICS link to your Full Slate account under Schedule > More > Sync, Import & Export > 'Synchronize Full Slate with an external calendar' > 'Add connection' > 'Subscribe to another external calendar'. Please note we do not currently support the "Webdav" protocol.
Please be aware that anytime two disparate programs are connected, it's not possible to guarantee 100% accuracy. As a result, we recommend not fully relying on a sync or subscription to operate your business. The safest approach is to check your schedule directly on Full Slate, whether on the web or mobile.