Esta consulta retornará Tablename e o número de registros que possui.
SELECT
TABLE_SCHEMA AS 'Database',
TABLE_NAME AS 'Table',
TABLE_ROWS AS 'Rows'
FROM
information_schema.TABLES ;
Esta consulta retornará bancos de dados no servidor w.r.t. Tamanho * /
SELECT
TABLE_SCHEMA AS 'Database',
SUM((data_length + index_length) / (1024 * 1024)) AS 'Database_Size'
FROM information_schema.TABLES
GROUP BY table_schema
ORDER BY 'Database_Size' DESC
LIMIT 5 ;