example_pdf.rb

require 'prawn'
require 'prawn/table'

module Spree
  class ExamplePdf < Prawn::Document

    HEADER = ['I', 'II', 'III', 'IV']
    WIDTH = 200

    def initialize
      super(page_layout: :landscape)

      numbers = { 'uno' => { 'one' => [[1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4]], 'four' => [[1, 2, 3, 4]] }, 
                  'dos' => { 'one' => [[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4]] }, 
                  'tres' => { 'one' => [[1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4]] },
                  'cuatro' => { 'one' => [[1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4], [1, 2, 3, 4], [1, 2, 3, 4]]},
                  'cinco' => { 'one' => [[1, 2, 3, 4], [1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4]] },
                  'seis' => { 'one' => [[1, 2, 3, 4]], 'two' => [[1, 2, 3, 4]], 'three' => [[1, 2, 3, 4]] }}

      data = []

      numbers.each do |spanish, elem|
        table_data = []

        elem.each do |english, int|
          english_row = [{ content: english, colspan: 4 }]
          sub_table = make_table(int.unshift(english_row), header: true, width: WIDTH)
          table_data << [{ content: sub_table, colspan: 4 }]
        end

        spanish_row = [{ content: spanish, colspan: 4 }]
        spanish_table = make_table([spanish_row] + table_data, header: true, width: WIDTH)
        data << [{ content: spanish_table, colspan: 4}]
      end

      table([HEADER] + data, header: true, width: WIDTH)
    end
  end
end

__END__

pdf = Spree::ExamplePdf.new
pdf.render_file 'oonu.pdf'
save_path = Rails.root.join('/Users/YOUR_USERNAME/Desktop','oonu.pdf')
File.open(save_path, 'wb') do |file|
file << pdf.render
end