it's hard to explain so i have made a video:
It looks like you have a pretty ridiculous scale for the scene
The left side of the table seems to be around 0, the right around 600 - That means you're moving around 100 meters per second just moving slowly
On the other hand it could have been the video compression making the numbers near unreadable ;)
If your values are that high, i'd suggest scaling the scene down, as you'll never get decent physics response like that
If they're not that high, then I'd check the physics materials you're using to make sure you're not using bouncy on everything including the tank, that'd make things a little nutty
have you tried changing the size of the entire scene altogether? if everything in the scene is ridiculously huge or crazy small something like that could easily happen. try making the tank and like a single box alot bigger/ alot smaller just to see.
if your using blender to make the models, make sure you press ctrl+a before saving to apply the correct orientation and scale to the objects.