Thank you so much for your question regarding our theme Mercantile.
If you want to hide such meta tags, you have three methods.
1. Simple method is, purchase the premium theme and use it. Premium theme have lots of additional features and you can easily manage everything on your site including meta, slider, sidebars etc. Check premium products here.
2. Customize the theme code. Find the codes on theme file and customize it. Note: Child theme is recommend to customize the theme.
3. Use the below CSS codes on Appearance > Customize > Additional CSS to hide the meta from the blog page.
Hope, you choose the best suitable method for your website.
You can read this blog post to know more about the theme as well.
If you have any query, feel free to ask.