When VSTO code creates a list object and applies a table style in Excel 2007, the Table Tools/Design tab is activated automatically. When the user then selects a non-table
I don't think you'll consider this an "answer" but the best thing I could find was someone on MSDN suggesting I assign a keyboard shortcut to the ribbon and then using Application.SendKeys to select it when I assumed the user will need to see the ribbon (on startup after I create the initial table, etc.)
Best of luck to you, and I hope you find a better answer - I will gladly update my application in that case!