Coronation Chicken or Delia's Tarragon chicken. Quiche. Perhaps good quality sausages. Then what Cies said.
However, slices of ham/beef can be difficult to eat if not everyone can sit down at a table.
Salmon easy to eat with just a fork. A caterer I know always recommends having the salmon filleted and then cut into little triangles before cooking - easier to pick up although a whole salmon looks really impressive.