1 таблица

CREATE TABLE [dbo].[test1](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Name] [nvarchar](50) NULL,
 CONSTRAINT [PK_test1] PRIMARY KEY CLUSTERED 
(
    [Id] ASC
)WITH (
     PAD_INDEX  = OFF, 
     STATISTICS_NORECOMPUTE  = OFF, 
     IGNORE_DUP_KEY = OFF, 
     ALLOW_ROW_LOCKS  = ON, 
     ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

2 таблица

CREATE TABLE [dbo].[test2](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Name] [nvarchar](50) NULL,
[RelId] [int] NOT NULL,
CONSTRAINT [PK_test2] PRIMARY KEY CLUSTERED 
(
[Id] ASC
) WITH (
    PAD_INDEX  = OFF, 
    STATISTICS_NORECOMPUTE  = OFF, 
    IGNORE_DUP_KEY = OFF, 
    ALLOW_ROW_LOCKS  = ON, 
    ALLOW_PAGE_LOCKS  = ON) 
    ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[test2]  
    WITH CHECK ADD  CONSTRAINT [FK_test2_test1] FOREIGN KEY([RelId])
REFERENCES [dbo].[test1] ([Id])
GO

Сам триггер

CREATE TRIGGER test1_insertupdate
    ON  dbo.test1
    AFTER INSERT, UPDATE
AS 
    DECLARE @Id int, @Name nvarchar(50)
    SELECT  @Id = (SELECT Id FROM inserted)
    SELECT @Name  =(SELECT Name FROM inserted)
    BEGIN
        INSERT INTO dbo.test2 (RelId, Name) VALUES(@Id,@Name)
    END
GO