Select the range you want to turn into a table then go to 'Add-ons > Sheets to Reddit table > Active Range'. An alert will then appear with the table for you to copy and paste. The top row of the range will be used as headers.
Use this add-on to post your Google Sheets data straight to /r/googlesheets and other subreddits. You can also copy the markdown table for use anywhere else. Formatting can be retained. The add-on includes a custom function for generating tables within cells.
This add-on has no affiliation with Reddit. REDDIT is a registred trademark of reddit inc.