Heres an idea for when children arrive at a party.  Before the party starts hide name badges and/or chocolate and sweets around the hall or garden.  As the children arrive ask them to look for their name or sweets.  this keeps them occupied until everybody has arrived.  Remember not to hide things too well and not too high.  If you can have some helpers to put name badges on and to help any younger children who can’t read yet this will help.