after using eurostar for the first time this w/end, i would suggest not taking any bag that is bigger, than the size you can take on a plane as hand luggage. the racks at the end of the carriage, are no way big enough to take more than a few large suitcases, and unless you get on at St Pancras, you just dont have the time or space to fit your bags in. at least if you take small bags, there is ample room inside the seating compartment, on racks over your head. we found this also the best place to put an umbrella fold pushchair, as other passengers take no consideration of other peoples luggage, and just throw it out the way, or dump their stuff on top of it. also the luggage racks, are a mad scrammble when the train pulls into the station, so at least if you have your bags stored near your seat, you can just pick them up and go, avoiding the scrummage
Flea