procedure TForm1.tblItemBeforeDelete(DataSet: TDataSet);
begin
  Memo1.Lines.Add(Format('deleting Item JobID %u ItemID %u',
    [tblItemJobID.Value, tblItemItemID.Value]));

  // delete records from last to first
  tblMat.Last;

  while tblMat.RecordCount > 0 do begin

  // if you uncomment the tblMat.Last then no error occurs but the 
lines
  // logged to Memo1 show that the table position before and after 
Last is
  // different - I 
don't think this should be the case as after a Delete
  // at EOF the table should automatically position itself at the next to
  // last record

//    Memo1.Lines.Add(Format('Del 
JobID %u ItemID %u ResID %u... (Before 
Last)',
//      [tblMatJobID.Value, tblMatItemID.Value, tblMatResID.Value]));

//    tblMat.Last;

    Memo1.Lines.Add(Format('Del 
JobID %u ItemID %u ResID %u... (After Last)',
      [tblMatJobID.Value, tblMatItemID.Value, tblMatResID.Value]));

    tblMat.Delete;
  end;
end;