If you want to insert/update several tables at once, you would be better off using a stored procedure. Create/Read/Update/Delete (CRUD) stored procedure are generally good practice and reduce the risk of SQL injection attacks.
Here's what your Create (insert) stored procedure might look like (it's incomplete and unnormalized):
CREATE PROCEDURE [dbo].[ApplicantIns]
(
@Name nvarchar(50)
,@Skill nvarchar(5)
,@Age int
,@comment nvarchar(50)
)
AS
SET NOCOUNT ON;
INSERT INTO [dbo].[Applicant]([name]) VALUES(@Name);
INSERT INTO [dbo].[Skillset]([Skill], [Comment]) VALUES(@Skill,@Comment);
INSERT INTO [dbo].[Statistics]([Age]) VALUES (@Age);
You could then call this stored procedure when someone submits a new application.