Pourquoi mes données PostgreSQL de Discourse sont-elles trop volumineuses ?

This is the output of my forum for these commands. I think the first 5 rows are consuming too much space. I cant imagine why user_actions should be around 2GB. Or post timing about 1GB. Can you give me an idea what could be wrong?

On the other hand, is there any way to clean unnecessary data? For example maybe I can get rid of most of email_logs. I don’t send too many emails. I don’t know why this is so big.

 public.user_actions     | 1792 MB
 public.email_logs       | 1293 MB
 public.post_timings     | 731 MB
 public.directory_items  | 456 MB
 public.topic_views      | 446 MB
 public.posts            | 380 MB
 public.post_search_data | 298 MB
 public.notifications    | 170 MB
 backup.topic_views      | 156 MB
 public.post_actions     | 155 MB
 public.user_histories   | 134 MB
 backup.directory_items  | 123 MB
 public.user_auth_tokens | 110 MB
 public.users            | 91 MB
 backup.user_auth_tokens | 87 MB
 public.user_visits      | 77 MB
 backup.posts            | 68 MB
 backup.post_timings     | 65 MB
 backup.post_search_data | 64 MB
 public.optimized_images | 63 MB