for row in ws.iter_rows(min_row=3, max_row=13, min_col=13, max_col=13):
    for cell in row:
        symbol_cell.append(cell.value)

for row in ws.iter_rows(min_row=3, max_row=13, min_col=13, max_col=13):
    [symbol_cell.append(cell.value) for cell in row]

[symbol_cell.append(cell.value) for cell in row for row in
 ws.iter_rows(min_row=3, max_row=13, min_col=13, max_col=13)]