Create this relationship:
Invoices::LogoTitle = LogoTable::LogoTitle
Add the container field from LogoTable to your Invoices layout.
Format Invoices::LogoTitle with your drop down of Logo Titles and when you select a title in the drop down, the logo will appear on your Invoices layout.
Thank you very much as always!!! It definitely worked!
It was just a simple fix.. I have to really get a glasp of the "table relationship" because my brain is so used to the php/mysql type.