require 'nokogiri'

file = File.open('personaskills.htm')

html = Nokogiri::HTML("http://persona4.wikidot.com/skill") #скачивал файл, для вас написал ссылочку на сайт

table = html.css('table.wiki-content-table')[0..2]
skills_table = table.css('tr')
titles = table.css('tr > th')

titlesRaw = []

(0...titles.length).step(7) { |i| titlesRaw.push(titles[i].text) }

titlesFinalized = titlesRaw[0..-4]
titlesFinalized.push("Follow Up Attacks", "Rise's Support Skills", "Passive Skills")

skills = {}

element = ""

count = 0

skills_table.each do |row|
  if row.css('th').text == titlesFinalized[count]
    element = titlesFinalized[count]
    count += 1
  else
    if row.css('th').text == ""
      if row.css('td').length == 6
        name = row.css('td')[1].text.downcase
        name.gsub!(/['),. ]/, "")
        name.gsub!(/[(-]/, "_")
        skill_name = row.css('td')[1].text
        skill_description = row.css('td')[2].text
        skill_cost = row.css('td')[3].text
        skill_target = row.css('td')[4].text
        skills[name] = {name: skill_name, element: element, desсription: skill_description, cost: skill_cost, target: skill_target}
      elsif row.css('td').length == 5
        name = row.css('td')[1].text.downcase
        name.gsub!(/['),. ]/, "")
        name.gsub!(/[(-]/, "_")
        skill_name = row.css('td')[1].text
        skill_description = row.css('td')[2].text
        skill_target = row.css('td')[3].text
        skills[name] = {name: skill_name, element: element, desсription: skill_description, target: skill_target}
      elsif row.css('td').length == 4
        name = row.css('td')[1].text.downcase
        name.gsub!(/['),. ]/, "")
        name.gsub!(/[(-]/, "_")
        skill_name = row.css('td')[1].text
        skill_description = row.css('td')[2].text
        skills[name] = {name: skill_name, element: element, desсription: skill_description}
      end
    end
  end
end

puts skills["agi"]
puts skills["agi"][:cost].inspect
puts skills["agi"][:description].inspect