org-enable-table-editor

org-enable-table-editor is a variable defined in `org.el'.
Its value is

optimized

Documentation:
Non-nil means lines starting with "|" are handled by the table editor.
When nil, such lines will be treated like ordinary lines.

When equal to the symbol `optimized', the table editor will be optimized to
do the following:
- Automatic overwrite mode in front of whitespace in table fields.
This makes the structure of the table stay in tact as long as the edited
field does not exceed the column width.
- Minimize the number of realigns. Normally, the table is aligned each time
TAB or RET are pressed to move to another field. With optimization this
happens only if changes to a field might have changed the column width.
Optimization requires replacing the functions `self-insert-command',
`delete-char', and `backward-delete-char' in Org-mode buffers, with a
slight (in fact: unnoticeable) speed impact for normal typing. Org-mode is
very good at guessing when a re-align will be necessary, but you can always
force one with M-x org-ctrl-c-ctrl-c.

If you would like to use the optimized version in Org-mode, but the
un-optimized version in OrgTbl-mode, see the variable `orgtbl-optimized'.

This variable can be used to turn on and off the table editor during a session,
but in order to toggle optimization, a restart is required.

See also the variable `org-table-auto-blank-field'.

You can customize this variable.