Why did a 10 minute video take up 32GB of space? (Canon 1200D)
For one thing, that chart doesn't list 1920x1080 @ 50 fps, which is what you're shooting.  It lists 1920x1080 at 24, 25, and 30.  You can assume that you'll get around half the recording time listed when you double the frame rate.   But that should still get you around 44 minutes on an otherwise empty 32 GB card.  The fact that you didn't suggests that your card didn't have 32 GB of free space.  You probably had other pictures, movies, or files on the card already.  To get the full available recording time, you'll need to follow the manual's instructions on "formatting" the card.  Formatting a card erases all of its contents, so make sure you copy anything you want to keep over to a computer first.