Hmmm, mixed feelings really! You wouldn't usually have an accompaniment but maybe some little gem leaves that you can use as wraps for some of the platter components.
Appropriate dips, sauces etc for each component would be my priority and then serve a course to balance things out.
potato and apple salad (Michael Smith has a brilliant recipe with the cooked spuds allowed to cool in basalmic (I have added a smidge of maple syrup), then add apples covered in lemon juice and then a mayo/yohgurt mix, well seasoned and chives).
Eccles, I tend to agree with you. When I've had a fish platter, normally I would just have the fish. However, I was thinking it looks a bit mean (even if the lobster is going to cost a small fortune).
If you want to cut corners with some of the cooking and preparation, Sainsbury’s do some very nice king prawns with a chilli dip. I don’t usually buy ready-prepared food, but because I like prawns I thought I’d try them. Very nice indeed.
Thinking back to every seafood platter that I have had either in he UK or in USA I have never had any sides other than crusty bread to sop up the hot butter that came on some of the prawns or scallops.
Well all I do is chop some crispy salad add croutons and then mash up some Avocado spritz of lime juice in it ( or not) to taste then layer it with seafood. Funnily enough lad it with lobster last night and a salmon fillet :)
I really can't remember what they're called - chunks of raw veg for dipping would be nice.
Anything fresh and light that doesn't overpower the flavours of the seaside but provides a different texture.
Some of your guests may be avoiding bread.