Couple of ideas for iSCSI share bulk deletion...
1) A simple way to delete iSCSI shares on a per "card" basis. there could be a delete option in the "hamburger" menu for each card onteh iSCSI manager page.
2) For Bulk share deletion, i envision a wizard, side panel, or page that LISTS all the iSCSI shares (filtering options would be good also; by share name or server name) with check boxes next to each or a select all. once selected either a button to choose delete or action drop down menu with delete.