...This information I'm passing through my DAL in VB ...how do insert this information from table1 and table 2 into the tablelink? Hope this makes sense?
First of all, it looks like you don't need TableLinkID for TableLink table. If it's true (if there are no tables that reference to specific record in TableLink) - I would recommend you to remove it and set primary key to (TableID, Table2ID).
Still not clear what are you trying to ask. I assume that Table1 and Table2 have identity columns and you are using Dataset (or Typed Dataset) and DataAdapter (or TableAdapters for Typed Dataset) as DAL. If no - please describe your DAL.
If you want to add a new record to Table1 and immediately (without saving changes to DB) start adding related items from Table2 (thus inserting records into TableLink):
In this case you will encounter the problem when identity column is not set for Table1 yet, so you cannot insert records into TableLink DataTable (because you don't know TableID for newly-created Table1 record).
Solution - before adding DataRows to TableLink you have to save Table1 changes to DB, and it will automatically update the TableID column of Table1 DataTable to correct value.
If it doesn't answer your question, please describe how do you handle the relations between Table1 and Table2 on client - do you have a TableLink DataTable, or you have some custom collections, or smth. else. Try to submit parts of the code (or some pseudo-code) that will describe what are you trying to achieve.