I've been using Windows 8 exclusively at home for a few months now and haven't experienced any problems in IE, Chrome, or Firefox. The problem you're describing sounds a lot like a zoom issue. Reset your zoom (usually with something like ctrl+0) and see if that fixes the "awkward".
I've gone back to wondering if it does have something to do with your Tablet display layout. Considering the images you have posted, the Daniweb website is looking proportionally narrower than what it would do in a typical Landscape view. So, although your view is Landscape, your browser seems to have formatted it for Portrait.
My laptop/tablet diplays the DW site in the same way as yours does, and I just put it down to a tablet thing.