I want to tell a colleague not to eat at her desk
Is she not allowed to eat at her desk? What's going on?
I don't like her. She eats repulsive junk food all the time, which stinks to high heaven. I can't stand it any longer.
You can't tell her to stop eating at her desk simply because you dislike her. You can either ask her to eat elsewhere or during that time, you should go elsewhere.
Wait, what? I didn't think of looking for a different table or working from home or something else. Should I do that instead of whining about it?
That's a much better idea. I think the animosity you feel towards her could potentially cause conflict. Settling it without an issue is the best route for everyone.