Will be arriving at Brussels Airport about 10PM and want to go to my hotel in Ghent. Best wat at that time of night?
The easiest method would be train. The shortest options (less than an hour ride) involve a change in Brussels, but there are direct trains that take a little longer (about 90 minutes). You didn't mention when you're traveling, but when I entered a date next week, it shows the last train leaving the airport at 23:51. That's more than enough time to deplane and clear immigration in Brussels, provided your flight lands on time.
I don't know how late the trams run in Gent, but because it's a university town, I would imagine rather late.