Add a wrapper around tables to allow overflow on Jekyll websites

style.css

.table-wrapper {
    overflow: auto;
    padding-top: 10px;
    padding-bottom: 10px;
}

table_wrapper.rb

# _plugins/table_wrapper.rb

Jekyll::Hooks.register :documents, :post_render do |doc|
  doc.output.gsub! /<table>/, '<div class="table-wrapper" markdown="block"><table>'
  doc.output.gsub! /<\/table>/, '</table></div>'
end

For GitHub pages users, with no support for custom plugins: you can get the same effect using Liquid's replace.

{{ content | 
    replace: '<table>', '<div class="table-wrapper" markdown="block"><table>' |
    replace: '</table>', '</table></div>' }}