If you think the Talisman board is big just look at this Arkham Horror game!!!
we're going to need a bigger table
Just because you can setup all the expansion board length-wise, doesn't mean it's necessarily the best option. I prefer this myself:
www.boardgamegeek.com/image/492127
Adding 1/3 to length and 1/3 of length to width.
It's just crazy if you look at it..