VB.NET - temporary data in datagridview

Hi,

I am building desktop application using VB.NET framework.

Form contains two set of data.

1. Project related data - contains text boxes.
2. Allocate team to project - Popup window will open and from there will allocate team members to project and close window. Here I want to show this data in main form Datagridview. However its only temporary basis.
3. After clicking Save button want to save data in database.

However, next time when I load main form it should display data from database and also new data which will added from popup window. Kindly help how to build this. Also, suggest alternative methods if any.

Thanks