Within a segment, the following bulk options are available to quickly manage your contacts:

Check the needed contacts to access the bulk options.

Selecting Add to Campaign allows you to add contacts to an automation campaign. Search for the automation or select multiple ones to add the contact.

Manage tags opens the tag management window, allowing you to add tags to the selected contacts. Multiple tags can be added.

Email opt-in lets you subscribe or unsubscribe a contact from email marketing.

Remove selected will remove the contact from this particular segment. This will not remove the contact from your account as a whole.