I don't see why the parent that is with the children in the evening can't eat at the same time as the children!?
You can still spend time with the other parent when he comes home and has his dinner.
Yes children need smaller meals and more often. However, it can work around your 3 meals a day.
Breakfast together,
Snack - carrot sticks, cucumber sticks, cheese cubes, fruit, brown bread, my children loves it when we sit and cut fruit up together and they get to choose what fruit they want.
lunch - together
Snack - as above snack
dinner - together
It is going to confuse them if they see you either running around whilst they are supposed to be sitting quietly eating. What you seem to be doing looks much more interesting. You need to strike a balance though, they don't need you sitting there staring at them and "pressurising" them into eating. Why should they eat when you are not.
If for example you would like them to eat fruit, get them to choose the fruit they want, sit down with them and cut it up for them, eat a bit of it yourself.
They should not be offered anything else. That's is the way we have done it with our children. Most of the time they eat cauliflower, carrots, cucumbers, etc. and sometimes they don't.
It is the same with adults though, sometimes I like to have a carrot sometimes it is the last thing I fancy.