More than one row is selectable by setting selectionMode to multiple. By default in multiple selection mode, metaKey press (e.g. ⌘) is necessary to add to existing selections however this can be configured with disabling the metaKeySelection property. Note that in touch enabled devices, DataTable always ignores metaKey.
The header checkbox toggles the selection state of the whole dataset by default, when paginator is enabled you may add selectAll property and select-all-change event to only control the selection of visible rows.