MySQL 8.0

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create table tbl (
  id int,
  text varchar(100)
);

insert into tbl values
  (1, '</table> 
 
 
</li>
</ul>'),
  (2, '< /table>   
 
 
< /li>
< /ul>');
select * from tbl;


id
text


1
</table> 
 
 
</li>
</ul>

2
< /table>   
 
 
< /li>
< /ul>


select
    REGEXP_REPLACE(
     text
    ,'<[[:blank:][:space:]]*\/table>[[:blank:][:space:]]+<[[:blank:][:space:]]*\/li>[[:blank:][:space:]]+<[[:blank:][:space:]]*\/ul>[[:blank:][:space:]]*'
    ,'</table>'
    ) text
  from tbl;


text


</table>

</table>


update tbl
  set text = REGEXP_REPLACE(
     text
    ,'<[[:blank:][:space:]]*\/table>[[:blank:][:space:]]+<[[:blank:][:space:]]*\/li>[[:blank:][:space:]]+<[[:blank:][:space:]]*\/ul>[[:blank:][:space:]]*'
    ,'</table>'
    )
select * from tbl;


id
text


1
</table>

2
</table>