MySQL provides metadata of the database itself, basically just run this on your query. Don't forget to replace database name with yourown database name.

SELECT
  TABLE_NAME AS `Table`,
  ROUND((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024) AS `Size (MB)`
FROM
  information_schema.TABLES
WHERE
  TABLE_SCHEMA = "replace_with_your_database_name"
ORDER BY
  (DATA_LENGTH + INDEX_LENGTH)
DESC;

Credit, thanks to: https://chartio.com/resources/tutorials/how-to-get-the-size-of-a-table-in-mysql/