Enabling Pipelines emails caused the 'services' table to increase by 200GB in one hour

Summary

Enabling Pipelines emails caused the 'services' table to increase by 200GB in one hour. How can I safely clear the 'services' table now ?

Steps to reproduce

Admin Area > Service Templates > Pipelines emails:( Active: + , Recipients: my email)

What is the current bug behavior?

After enabling the "services" table, it started growing with this data:

921780211 | PipelinesEmailService | Pipelines emails | 596 | 2019-10-17 11:21:45.618876 | 2020-05-27 16:05:15.876159 | t | {"notify_only_broken_pipelines":"1","notify_only_default_branch ":"1","recipients":"my_mail@exemple.com"}

several hundred lines per second

What is the expected correct behavior?

Relevant logs

Relevant logs

Details of package version

ii gitlab-ce 12.0.0-ce.0 amd64 GitLab Community Edition (including NGINX, Postgres, Redis)