Convert Array CSV to Object using Header
You can also use built-in methods such as map and reduce. According to JSPerf they are as fast and the code is shorter, so you could potentially get rid of the Underscore dependency:

function csvToObject2(data) {
  return data.slice(1).map(function(xs) {
    return xs.reduce(function(acc, x, i) {
      acc[data[0][i]] = x
      return acc
    },{})
  })
}