Yes, but the pressurised tank is metal (I guess) and it probably contains 3 litres of water. Then there's a pump and a motor and a few metres of heavy duty power cable.
Just for you raamv, I weighed mine: 10 kgs... IIRC there is about 1 litre of water still in the tank (at the most) from last time I used it (yesterday).
The wet and dry cleaner in the K Rauta rag is probably lighter because it contains an empty cyclinder for dust, and the pressure chambre would be smaller than mine. I'm sure you can find the weight of it somewhere on karcher.com or wherever.