> Roundup isn't a pesticide, or an insecticide (as the charts above are labeled). Roundup is an herbicide

Pesticide is an umbrella term for herbicides, insecticides, and other types of substances. If you've read the paper, it mentions that too:

> Pesticides are substances used to repel, kill, or control animals (insecticides) or plants (herbicides) that are considered to be pests.

You are correct, though, in that while insecticide use decreased (because GMOs help insect resistance), herbicide use has actually increased because of herbicide tolerance of GMO crops.