Can the Target__c field be deleted in the CRM Account object?
No. This cannot be deleted.
The Target__c field does not have out-of-the-box functionality, but can be used to indicate if an Account is a target. This field can also be used for triggers or workflows depending on business needs.
Even though the Target__c field does not have _vod in the naming convention, this is identified as a Veeva field to perform such actions as environment upgrades and maintenance to Orgs.
This field should not be deleted or modified (other than the label).
CRM Help Documentation: