Your settings seem fine, i think those layer lines are just in the nature of printing slight differences in height with FDM. You could try 0.1mm layer height but that’s going to increase your print time significantly.
My suggestion would be to re-orient the tile to print on its side instead of flat. If you print with a brim or raft it should be stable enough. Whilst you might get some horizontal layer lines they’re much easier to sand down.
Hope that helps