table.haml

%table
  %tr
    %th
      Foo
    %th
      Bar
  = rows

table.rb

class Table < ::Cell::Concept
  include ActionView::Helpers::TranslationHelper

  inherit_views Group::Cell

  def show
    render :table
  end

  def rows
    groups = Group.all
    concept("group/cell", collection: groups)
  end
end