SQL Server 2008 :: Insert Data Into Table Variable But Need To Insert 1 Or 2 Rows Depending On Data

I am writing a query to return some production data. Basically i need to insert either 1 or 2 rows into a Table variable based on a decision as to does the production part make 1 or 2 items ( The Raw data does not allow for this it comes from a look up in my database)

I can retrieve all the source data i need easily but when i come to insert it into the table variable i need to insert 1 record if its a single part or 2 records if its a twin part. I know could use a cursor but im sure there has to be an easier way !

Below is the code i have at the moment

declare @startdate as datetime
declare @enddate as datetime
declare @Line as Integer
DECLARE @count INT

set @startdate = '2015-01-01'
set @enddate = '2015-01-31'

[Code] .....