If you have added a Data Card widget for any object, the portal users will get the records of the selected object in the data card (grid view).
Here the order object’s records are shown in the Data Card view.
The portal users can also delete multiple records as you have given the delete rights. Portal users can select the Object records in bulk and by clicking on the Delete Records button beside the Create button or Delete icon on the card.
The portal users can export the Object records in the CSV. Select all or select required records to export in CSV and click on the Export CSV, it will export the CSV file of the selected records.
Portal users can also filter the records, if you have enabled the advance filter from the list view of the Data Card widget.
Portal users can also edit the records by clicking on the Edit icon, if you have given edit rights to them.