const columns = [
        { title: "Name", data: "name" },
        { title: "Description", data: "description" },
        { 
          title: "Tags", 
          data: null,
          defaultContent: '',
          sortable: false,
          ngTemplateRef: {
            ref: this.tagsTemplate,
          }          
        },
        {
          title: "Actions",
          data: null,
          defaultContent: '',
          sortable: false,
          ngTemplateRef: {
            ref: this.actionsTemplate,
            context: {
              // needed for capturing events inside <ng-template>
              captureEvents: self.onCaptureEvent.bind(self)
            }
          }
        },
        { title: "Id", data: "id", visible: false }, // invisible columns need to be after templateRef column
      ];

<ng-template #actionsTemplate let-data="adtData" let-emitter="captureEvents">
  <app-ico-datatable-action [data]="data" (emitter)="emitter($event)" ></app-ico-datatable-action>
</ng-template>

<ng-template #tagsTemplate let-data="adtData">
  <span *ngFor="let tag of data.tags">
    {{tag.key}}: {{tag.value}}<br />
  </span>
</ng-template>