Right now over half of the slayer monsters have worse drops than goblins. These include, but are not limited to:
Cave crawlers, Cave slimes, Cave bugs, Bloodvelds, Warped Terrorbirds, Cave Horrors (excluding black mask), Aberrant spectres, Goraks, Nechs, and many more monsters that can be gotten as a task but require no slayer level. Goblins have 10 hp, some of these monsters have 100+. Either nerf the goblins or buff these.
Edit: I suggest adding either an alchable table (similiar to the goblin one where there's a lot of rune items on the same roll, but you only get one), more noted/stackable items or even experience lamps.