Is it possible to add a "list by entries"?

The ESGST script might be able to do it. I know it has sorting features, but I'm not sure what it can do.

Also, you can't sort right now, but you can choose to only see giveaways with a certain minimum or maximum number of entries if you want by adding entry_min= or entry_max= to the url as shown here.

This will show you all the giveaways with over 10,000 entries: https://www.steamgifts.com/giveaways/search?entry_min=10000