Opodiphthera is an interesting suggestion. Did you see them being laid,? Or have you seen eggs spaced like this from Emperor moths previously? I have never encountered any. If not, then other insects besides moths may have laid them. If you can keep them and rear them, it would be good to have documentary evidence of their species.
This is just what Opodiphthera eggs look like. The spacing varies. I photographed some on a young Eucalypt a few days ago one egg had hatched and there was a lovely Opodiphthera helena larvae nearby.
That photo is hardly a natural placing of the eggs - on ?plastic ?glass. In nature they lay on the foodplant. The hatchlings do not disperse by 'ballooning' like some lepidoptera larva do. For hatchlings to survive mum needs to have placed the eggs on a foodplant. see Sighting 4564982, 4462446 & 4616234