Does anyone know how to delete the header of lightning datatable, and how to put data parts only?
Just to complement Oleg's answer, you can always check official documentation for lightning base components at https://developer.salesforce.com/docs/component-library/overview/components. For
lightning:datatable specifically - https://developer.salesforce.com/docs/component-library/bundle/lightning:datatable/specification. There you will find all available attributes and examples with sample code.