gistfile1.js

// Convert an HSBC "previous statement" page into a CSV

var year = 2013,
    months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

var output = '',
    rows = $('table').last().find('tr');

rows.each(function(i, row) {
  if(i === 1 || i === rows.length - 1) return;

  var cells = $(row).find('td');

  var date = $(cells[0]).text().trim(),
      desc = $(cells[2]).text().trim(),
      debited = $(cells[3]).text().trim()
      credited = $(cells[4]).text().trim();

  // Reformat date
  var day = date.split(' ')[0],
      month = months.indexOf(date.split(' ')[1]);
      date = (new Date(year, month, day)).toISOString().split('T')[0];

  var transaction = '';
  if(debited === "") {
    transaction = credited;
  } else {
    transaction = '-' + debited;
  }

  output += [date, desc, transaction].join(',') + "\n"
});

console.log(output);