Yes. If you no longer want someone in your Travel Mates list, you can remove them. They won’t be notified explicitly that you removed them, but they may notice that your status info is no longer visible and that you appear not connected.
If someone is bothering you or you had a falling out, you can also block them. Blocking will prevent them from contacting you or seeing your profile details at all.
Use blocking if simply removing them isn’t enough (for example, if they might still try to send messages or requests). The platform wants you to feel comfortable – you curate your mates list.