I was just going through my guest list with the intention of making a start on my table planner.. when I realised I have no idea some of the children's surnames because they have different fathers to their Mums current partner, etc.. there are no duplicate children's names though, is it a good idea just to put first names for children on the table planner board? Or should I just make the effort to find out their surnames? It's an informal wedding anyway, we only had first names on the invites.