Notice: Undefined index: tablefield in tablefield_field_widget_form() (line 246 of tablefield.module).

Problem occurs in a node edit form. If removing an existing file that has been uploaded (such as an image) this error shows. On save, all data from the table is deleted.

From line 246 of tablefield.module - 7.x-2.0-beta5:

  elseif ($form_state['submitted'] && isset($items[$delta])) {
    // A form was submitted
    $default_value = tablefield_rationalize_table($items[$delta]['tablefield']);
  }

Replacing this with the code that was in line 246 of tablefield.module - 7.x-2.0-beta4 seems to fix the problem:

  elseif ($form_state['submitted'] && isset($items[$delta]) && isset($items[$delta]['tablefield'])) {
    // A form was submitted
    $default_value = tablefield_rationalize_table($items[$delta]['tablefield']);
  }