How to spend 19:00 to 1:00 in Kiel? (from Ferry to Train)

• If it’s the ferry’s terminal stop, ask the ferry operator whether you can stay any longer on board because of your connecting train departing later in the night. I guess the ferry will reverse its direction. At least the long-distance ferries do. Nevertheless sooner or later passengers for the reverse direction get aboard, so you’ll definitely have to left the ship by then. It is probably the most convenient option, though, if/because there are (not-disgusting) toilets on the ship and you possibly have access to electricity/WiFi.
• Various activities listed at WikiVoyage. E.g. go to the movies as Weather Vane mentinoed, or you can go to a public swimming pool „Hörnbad“ (till 10 p.m. except Sundays). We all have been a bit short of exercise lately, right?
• In general, take the slow train in the direction of your destination until a common stop. Like smci said Kiel is boring. No reason to stay there longer than inevitable.
• If you feel safe with doing that: Meet someone. Maybe you’re a member of, I don’t know, a worldwide chess player community. Arrange a meeting with someone living there. Or just talk to someone in the streets. Make a curious observation and strike up a conversation with a passer‑by.

@Sebastian:
I’m not sure which way Allerleihrauh is going.
IC 390/398 aren’t listed in the departure table yet, because there will be a „minor timetable change“ midyear (2022‑06‑12).

I lived near Kiel some years ago, so I can suggest a few things, with a big caveat: I have no idea of what the current restrictions due to Covid are. For that, check the other answers. But this answer of mine might come useful in the future, when hopefully the pandemic is over.

If you leave your luggage at the station, and don’t mind walking a bit, you could have a Bavarian dinner and have a good homemade beer at the Kieler Brauerei if you want to walk 15 minutes (it’s a bit more than 1 km; just follow the Sophienblatt, it’s where all the shops are). It’s quite large, so unless it’s a Friday or Saturday night it won’t be too crowded and I’m sure the staff won’t mind you occupying a table for long, as there will be plenty of space for other customers.

If you don’t want to walk that much, I think the Vapiano near the station is a good choice, because if I remember correctly it’s a self-service, that is, waiters won’t come to your table, you have to take a tray and walk to the counter to get something, so if you stay for long at a table the staff will probably not mind. They serve Italian food; nothing spectacular, but it’s decent.

If you want to go to a pub, there are many, just pick one at random.

If you are into clubbing, the nightlife area is the Bergstraße, mostly between the Pogue Mahone and the SubZero. There should be the Luna (currently closed due to Covid) and a few more. Otherwise, closer to the station, I remember the Ben Briggs, where everything is ship-themed (check the pictures on Google Maps).

Others have already mentioned the urban stuff, obv. it depends what you like and what is currently allowed for you. But there are also nice outdoor things. If you can store your heavy luggage you could:

• Walk at the pier, along the way are bars and nice parks, like in this.

• Visit the beach. Take a bus to "Falckensteiner Strand Kiel" or "Schilksee Strandbad" or "Hafen Strande" on the Weest-Side or "Laboe" on the East-Side. The rides will take some time 40min+ but they are very beautiful locations at the beach. In Laboe and Strande are nice Restaurants, check google-maps for open hours. You can take nice long walks at all those beaches. In Strande & Schilksee you could even walk all the way to the light-lighthouse "Bülk". Bus rides however become sparse at late time, so check them first.

CinemaxX is right next to Kiel Hbf.

This evening The King’s Man – The Beginning is showing at 19:30 and 22:50.

Note: the movie dialogue is likely to be in German unless English is explicitly stated. The title I showed is just an example of screening times.

_{(Subject to Covid-19 restrictions – such as a check certificate?)}

The Kiel train station offers Luggage lockers near the platform 6a on the main floor.

Nearby there are 5 restaurants (Gastronomie) and a waiting room shown on the PDF map of the station. Most of the restaurants will assume that peaple are biding their time waiting for a train.

Once the luggage has been deposited, you can wander around.

In the main hall there is a small information kiosk, where you can ask when exactly your train arrives. Since many of the trains start here, that may be 10-15 minutes before departure.

Sources:

• Kiel Hbf (English) | Deutsche Bahn AG
  • Map Kiel Hbf PDF | 183.5 KB
  • Kiel Hauptbahnhof — Mein Einkaufsbahnhof
    • 1* 24 hours daily ; 1* midnight (0h) ; 1* 21h ; 1* 20h ; 1* 17h