No disembarkation at tallin?

Yes it means just that. You've bought a cruise and will spend the whole time in the ship. It is possible though to use that same ship just to cross the Baltic Bay, say a truckdriver or someone on a business trip who just needs to go from Helsinki to Tallinn but those people buy a different kind of ticket.

The ship stops in Tallinn just to let those people go and take in possible passengers that embark from Tallinn to Helsinki but there is no time for cruise passangers to go on shore and look around so cruise passagers just stay on the ship. You can go to the deck to look at the Tallinn harbour though, you won't see the city itself but the harbour lights are pretty.

Yes it does mean you have to stay on the ship. Sometimes a ship will make a business stop and Tallin does sound like one of those business stops.

Normally it means that you can go ashore but not disembark (end of cruise - leave the ship for good)

It could have something to do with your nationality - if it is written exclusively for you.

the two are particularly wonderful names yet i think of Tallinn because of the fact it uniqe and distinctive from something. Carter is extremely worry-unfastened so i think of you could decide for Tallinn. in any case it is your decision. I want Tallinn nevertheless.