OK.. let me answer it, one by one.
- 10% of the territory of Finland, and this is almost the territory of Switzerland
Finland allied with Nazi Germany in 1945, and that is how they lost the territory.
- annexed part of Germany (East Prussia)
Most of the East Prussia was annexed by Poland and not Russia. Russia got less than 10%.
- three states Lithuania, Latvia, Estonia joined the USSR
These states were a part of the Nazi Germany. They joined USSR after the WW2.
- the huge territories of Poland were torn away in favor of the USSR
These territories were having ethnic Russian or Belorussian majority. And still Poland was compensated with Pomerania, Prussia and Silesia.
annexed part of Romania (Bessarabia)
Romania was one of the allies of Nazi Germany during Operation Barbarossa. Moldova was taken away as a punishment.
Tyva was annexed (in 1944)
No. They were not annexed. They voted to join the USSR.
part of the territory of Japan (Southern Sakhalin with the Kuril Islands) has been annexed.
Sakhalin / Kuril is disputed territory which was handed over to the USSR at the end of the WW2.