Good morning, Rick.
Thanks for reaching out to our Microsoft Community Forum. Please accept our warmest regards and sincerest hope that all is well.
We understand that you're Excel application is always opened in a small window when you launch the app instead of opening in a maximized window.
An easy way to reverse this issue is to open Excel, maximize it, and then while holding down the Ctrl key close the Excel by clicking the "X" symbol at the upper right corner of the app. After doing that, the app should always open maximized when launched.
Feel free to reply to this thread if you need further clarification.
Sincerely,
Glenn Rue
Forum Moderator
Microsoft Community