Previously In the Salesforce classic, Salesforce stored all of the files for a parent record as an attachment object.
With Salesforce's new user Interface Lightning, All the files are stored under Content Version Object. With Content objects, you get better versioning, distribution, and security controls.
Notes and Attachments
related list you have seems to have records from the Attachment object. When you are uploading the new files it is properly loaded as Files (Content Version) and hence you see all of those actions.
Salesforce recommends you stay away from using Notes and Attachment related list in your app and instead use Files related list for files and Notes related list.
You can read about this here
From the docs
The 'Notes & Attachments' related list will eventually be phased out in favor of the individual 'Files' and 'Notes' related lists.
Also, Salesforce recommends you migrate all attachments to Salesforce Files and Notes to new Enhanced notes using help here.