Dynamic datagrid based on periods and categories

Hello,
I am trying to build a datagrid for keeping budgets. You can see an example under my explanations. I want that I can insert and update amounts for each period and category. My problem is that I don't know how I can code this. The difficult thing is that I want to start with a clean grid without any amount filled in. The end user has to fill the amounts for each category and period and do this for different years (selected via dropdown list). Can somebody help me away about how I best setup my database tables and how I can code this into VB of C#?
Thanks in advance!