I know that thanks to those old cartoons people think trolls eat gnomes but there's nothing like that in folklore. If anything gnomes tend to have the upper hand over trolls. There's stories about gnomes chasing trolls away from houses and churches with the use of magic, so these little guys can fend for themselves if they want.
I love how cute the troll is. I imagine him going from garden to garden, stealing those horrible gnome decorations and giving them names