I found this thread - Add more selection parcels to current datagrid able to select additional parcel(s) to current datagrid but is there possible to click a button to remove current any highlighted parcels on a map? Besides that, I found an error message. If the parcels have been selected and you accidentally reselect it again then you will get an error message. So can you ignore it or prevent the error message so the datagrid table will still got the same results from your early search instead of showing error message on datagrid?
Ken also provided code in fiddle: