SQL Server 2005, 2008, 2012, 2014 или 2016:
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE'
Показать только таблицы из определенной базы данных
SELECT TABLE_NAME
FROM <DATABASE_NAME>.INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Или,
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND TABLE_CATALOG='dbName' --(for MySql, use: TABLE_SCHEMA='dbName' )
PS: для SQL Server 2000:
SELECT * FROM sysobjects WHERE xtype='U'