[richnfamous]

They probably can't find the food that easily.

I'd suggest putting some food around and about where they can see it. They're opportunists and once they find your table, they'll get the idea.

I'd agree that there are not many 'waiting rooms', and also fencing that they can't see through. Small birds live in constant wariness of predators - cats and sparrowhawks etc - and a hawk could pop over the green fence and take them by surprise. 'Waiting Rooms' like bushes or perches of some sort help as the birds who aren't feeding will also sound the alarm for those who've got their beaks in the trough. They'll also allow the birds to see if more dominant/aggressive birds are feeding. Nuthatches, for example, won't often share the table with others.

Good luck with your efforts. I can sit for hours watching the way the birds interact around feeders/tables - it's real life, unlike Eastenders and they're better singers than on X Factor!