int32_t row_index = 0;
lv_obj_t * table;
lv_obj_t * add_btn;
lv_obj_t * add_btn_label;
lv_obj_t * sub_btn;
lv_obj_t * sub_btn_label;

static void add_btn_cb(lv_event_t * e)
{
  lv_obj_t * obj = lv_event_get_target_obj(e);
  lv_event_code_t code = lv_event_get_code(e);
  if(code == LV_EVENT_CLICKED)
  {
    row_index++;
    lv_table_set_cell_value_fmt(table, row_index, 0, "test%d", row_index);
    lv_table_set_row_count(table,row_index + 1);
  }
}

static void sub_btn_cb(lv_event_t * e)
{
  lv_obj_t * obj = lv_event_get_target_obj(e);
  lv_event_code_t code = lv_event_get_code(e);
  if(code == LV_EVENT_CLICKED)
  {
    row_index--;
    if(row_index < 0) row_index = 0;
    lv_table_set_row_count(table,row_index + 1);
  }
}

void test(void)
{
  table = lv_table_create(lv_screen_active());
  lv_obj_set_height(table, lv_pct(80));
  lv_obj_align(table, LV_ALIGN_TOP_MID, 0, 0);
  lv_table_set_cell_value_fmt(table, row_index, 0, "test%d", row_index);

  add_btn = lv_button_create(lv_screen_active());
  lv_obj_set_size(add_btn, lv_pct(30), lv_pct(15));
  lv_obj_align(add_btn, LV_ALIGN_BOTTOM_LEFT, 0, 0);
  lv_obj_add_event_cb(add_btn, add_btn_cb, LV_EVENT_CLICKED, NULL);

  add_btn_label = lv_label_create(add_btn);
  lv_label_set_text(add_btn_label, "add tabel row");
  lv_obj_center(add_btn_label);

  sub_btn = lv_button_create(lv_screen_active());
  lv_obj_set_size(sub_btn, lv_pct(30), lv_pct(15));
  lv_obj_align(sub_btn, LV_ALIGN_BOTTOM_RIGHT, 0, 0);
  lv_obj_add_event_cb(sub_btn, sub_btn_cb, LV_EVENT_CLICKED, NULL);

  sub_btn_label = lv_label_create(sub_btn);
  lv_label_set_text(sub_btn_label, "sub tabel row");
  lv_obj_center(sub_btn_label);
}