SQL Server 2000, 2005, 2008, 2012, 2014, 2016, 2017 ou 2019:
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE'
Para mostrar apenas tabelas de um banco de dados específico
SELECT TABLE_NAME
FROM [<DATABASE_NAME>].INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Ou,
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND TABLE_CATALOG='dbName' --(for MySql, use: TABLE_SCHEMA='dbName' )
PS:Para SQL Server 2000:
SELECT * FROM sysobjects WHERE xtype='U'