Table not render when use Redcarpet in Jekyll GitHub Pages?

For this question, it seems the important extension here is "tables".

However if you want more Github flavored markdown, there are a few more listed at http://sholsinger.com/2014/03/jekyll-github-flavored-markdown.

Combining with neizod's answer I ended up using.

markdown: redcarpet
redcarpet:
  extensions: ["no_intra_emphasis", "fenced_code_blocks", "autolink", "tables", "strikethrough", "superscript", "with_toc_data"]

Adding only markdown: redcarpet into _config.yml is not enough, It's also need the extensions part, e.g.

markdown: redcarpet
redcarpet:
  extensions: ["no_intra_emphasis", "fenced_code_blocks", "autolink", "tables", "with_toc_data"]