A searchable guide to the complete WordPress Icon Library (@wordpress/icons) package from Gutenberg.
import { Icon, header } from '@wordpress/icons';
<Icon icon={header} />
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M18.5 10.5H10v8h8a.5.5 0 00.5-.5v-7.5zm-10 0h-3V18a.5.5 0 00.5.5h2.5v-8zM6 4h12a2 2 0 012 2v12a2 2 0 01-2 2H6a2 2 0 01-2-2V6a2 2 0 012-2z"></path></svg>
header – WordPress Icon Library