watching videos are also much better on a tablet. There's no contest here.
I disagree with this. I can't envisage any scenario where I would prefer to watch a video while holding the screen as opposed to resting the screen on a flat surface in front of me or on my knee where no surface is available (in the absense of a fixed screen of course which is superior to both).
As for web browsing, if a seperate keyboard and mouse is available then I'd rate it above a touch interface by far. If no mouse is available then the decider would have to be how much text I need to write. For browsing I'd go with the tablet but for answering posts on a forum I'd go with the laptop.