create_words.rb

class CreateWords < ActiveRecord::Migration
  def change
    create_table :words do |t|
      t.string :text
      t.integer :frequency
      t.integer :mistakes

      t.timestamps
    end
  end
end

word.rb

class Word < ActiveRecord::Base
  #attr_accessor :text, :frequency, :mistakes
end

words.rake

task :words => :environment do
  File.open("all_words.txt").each do |w|
    word = Word.create(text: w.chop, frequency: 0, mistakes: 0)
    unless word.valid?
      puts word.errors.full_messages.join(', ')
    end
  end
end