I have DLNA ready Samsung TV at home. I've tested it with my router. Everything goes well.
Is it possible to connect the TV directly to a PC via ethernet cable? If so, how can configure the PC to handle it?
You could use a crossover network cable and fix the IP address of both your PC and the TV in the same subnet, but it would be simpler just to buy yourself a cheap router.
If you have a router, why arent you be connecting the TV to it? More than likely it is the router is what is providing your network connectivity, and you want everything to connect to it.
However, you can hook up the TV to the PC, using Internet Connection Sharing.
My gut feeling is that you think the TV needs to be hooked up to the PC to "get your stuff." However, the reality is the router is what everything should be connected to.