eurostar tickets include travel to another station in belgium. so you can train it to ninove or wherever your hotel is.
I found out recently that this is not necessarily the case as it depends on the fare class in which you booked your ticket, which, in plain language, means that if you bought a steeply discounted ticket, you may need to purchase a separate ticket for domestic travel in Belgium. If you get caught, then I think most conductors will be polite and understanding about it, but you will inevitably pay the higher tariff onboard compared to the ticket office / online purchase. Therefore, I suggest you reconfirm the inclusion / exclusion bit before you set off.
I found out recently that this is not necessarily the case as it depends on the fare class in which you booked your ticket, which, in plain language, means that if you bought a steeply discounted ticket, you may need to purchase a separate ticket for domestic travel in Belgium. If you get caught, then I think most conductors will be polite and understanding about it, but you will inevitably pay the higher tariff onboard compared to the ticket office / online purchase. Therefore, I suggest you reconfirm the inclusion / exclusion bit before you set off.