On Eurostar there is no weight limit for your luggage, but you should be able to carry and lift your bags safely. Each bag can be up to 85cm long at its widest point. There is also no restriction on liquids, meaning you can pack all of the toiletries you need for your holiday.
Luggage Allowances by Ticket type:
2 pieces of luggage, including rucksacks, bags and suitcases
1 small piece of hand luggage, e.g. handbag, laptop bag or briefcase
Pushchairs and prams travel for free in addition to your individual allowance. You'll just need to fold your pram and store it in the luggage rack above your seat
1 piece of luggage
1 small piece of hand luggage
Children under 4 travel for free with Eurostar, so they don't need a ticket. They have no luggage allowance and they'll need to sit on a grown-up's lap as they have no allocated seat