SELECT 
    TABLE_NAME                        AS "Table",
    table_rows                        AS "Nb enregistrements",
    ROUND(data_length / 1024 / 1024, 2)          AS "Données (Mo)",
    ROUND(index_length / 1024 / 1024, 2)         AS "Index (Mo)",
    ROUND((data_length + index_length) / 1024 / 1024, 2) AS "Taille totale (Mo)"
FROM information_schema.tables
WHERE table_schema = DATABASE()
ORDER BY (data_length + index_length) DESC;

virer le where pour avoir toutes les bases.