I went for two months to Europe also as a student. I had a 18-55 Nikon, a 50mm Nikon , a 24mm Nikon and a 35-135 MF Nikon, and my D40x.
I used mostly the kit lens, then the 24mm, then the 50mm and, maybe a couple of times, the 35-135mm.
The truth is, that in most of Europe you are always in tight spaces were the wider the lens, the better the photo. For landscapes and taking photos of buildings, I found 18mm to be in the long side for this.
Also consider were you are going to stay. I always felt "insecure" when I was at hostels regarding my camera. Nothing ever happened to me or my things, but I sometimes wished I had just taken my kit lens and a wider fast lens. Nothing more. This would have enabled me to travel lighter and feel "safer".
Even tho Europe is mostly very safe, petty crime is quite common, and the less things you need to take care of, the better.
And this takes me to my last point: travel with a good backpack that doesn't scream "big camera here!!" and that is able to accommodate some clothing and personal things. This way you can leave your big baggage wherever you are staying to study, and travel just with one pack for the weekend or a small trip. I bought a Kata backpack, which has a camera compartment big enough for the camera and 2-3 lenses, and also has space for some clothes and a laptop. It was probably the best investment for the trip.
So, my recommendation is to buy a wider lens if you enjoy taking landscape and building photos. The 50mm would be great for portraits, and it's very small. As for the long range 30-130mm, I honestly would say don't take it.
Lastly, don't take a monopod!
I took one, never used it. Silly me. Take a gorilla-pod, one those small tripods that can be attached to almost any surface. They are small and quite handy. Obviously taking a normal sized tripod is a big NO, too much bulk.
Hope this helps.