Armando,
Before thinking about tablet compatibility, I would first clarify a few points with your client:
Will this be a standalone solution, or does it need to integrate with your existing PC programs?
Is it intended for a single device, or potentially multiple devices?
Which operating system does the tablet use (Windows, Android, iPadOS)?
And very importantly: how much development effort are you and your client willing to invest?
If the tablet runs full Windows, your FiveWin application should work without major problems — perhaps with some UI adjustments for touch and screen size. I also remember that Mr. Rao has already done some groundwork in FiveWin regarding tablet support, such as detecting screen orientation and switching between portrait and landscape modes. That could be helpful if you stay within the Windows environment.
However, if it is an Android tablet or an iPad, then a Windows executable will not run directly. In that case, you would need either a remote desktop solution or consider a web-based approach.
From a long-term perspective, device-specific development can become limiting. A browser-based solution (for example a small web application or PWA) offers more flexibility and works across different devices and operating systems — but it also requires additional development effort compared to simply running an existing EXE on Windows.
In the end, the right decision depends on scope, integration requirements, and how much time and resources you are prepared to dedicate to the project.
Best regards
Otto