So, I am traveling on the Eurostar from London on my way to Amsterdam. I've never been to Europe, and I was wondering if there was anything I could do, or see, or eat near the train station instead of going straight through to The Netherlands. (It will be brunch time, so of course I though about Belgian waffles). I'm really just looking for something quick as I need to get on to Amsterdam, but thought it would be fun to something in the only country I am not staying in...just traveling through.

How much time have you got? There is not a whole lot to do directly around the station. If you are prepared for a walk there is a flea market in the Marolles district at Place du Jeu de Balle (every day 7 am to 2 pm), or on Sunday mornings there is a huge market around Midi itself - you would only have to walk outside the station to find it. It has a Middle Eastern flavour. Or if you have less time maybe you can find a waffle in the station, not sure what you'd find there:

http://www.shoppingmidi.be/

Lavandula

Thank you! I think I'm going to stow my luggage at the station, walk to the old part (Grand Place/ peeing kid statue) and then get a Belgian waffle and some Belgian beer for "brunch."

The direct route up Blvd Stalingrad is not that nice to walk IMO.
You can take metro 3/4 from Midi (any train leaving from underground platform towards Gare du Nord) for 3 stops to Beurs/Bourse at hit the old town from there. It costs only 1.70 per ride.

Perhaps this has changed, but it used to be that one's Eurostar ticket was valid for any city train leaving the station. (Unless this was only true if Brussels was end destination?)