Massively grown database | WordPress.org

Greetings,
I installed the plugin on my website fantasvaimec.it,
in addition to the Home Page, it is also present on this page:
https://fantasvaimec.it/sport/

just fetching feeds to show in backend, no posts to import.

Only after a few days I realized that the database has grown X3 and the bulk is in wp_posts and wp_postmeta and the only substantial change in recent days has been to use Feedzy.

Is this behavior normal? Even if it only shows the feeds does it still matter the posts? Will the database continue to grow dramatically?

Thank you

The page I need help with: [log in to see the link]