Nvidia may be working on a 2-in-1 tablet, according to code in the Nvidia Shield Experience software found by XDA-Developers. It suggests a device or user interface that could switch between three modes: desktop, tablet and dynamic. The former of the three starts up when there's a keyboard attached to the device, and XDA-Developers wrote of mentions of "start menu visibility" and "mouse hover control" in desktop mode as well.
Additionally, the code mentions a product going by "Mystique," potentially a successor to Nvidia's Shield line of tablets (the last of which released in 2015).
The source code, which dates back to last year and could therefore be out of date, mentions a 13.5-inch, 3000 x 2000 (3:2) LCD display. And while code shows Nvidia was at one point working on the Mystique project with Tegra X2 (t186), the successor to its X1 in the current Shield and the Nintendo Switch. But in more recent code updates, it appears that Nvidia has switched to the Tegra Xavier (t194) meant for AI computing or autonomous vehicles. XDA-Developers speculates it may be running in a low-power mode so that it could operate in a tablet or 2-in-1.
Nvidia declined to comment to XDA, referring the site to previous comments made by CEO Jensen Huang. Those include the fact that codenames appear in code all the time and that concepts or references to them "remain even when it becomes unlikely that the concept ever goes into production." Another suggested that Nvidia only makes products to make things "the world doesn't have" and not solely to take market share.
In this case, an Android tablet to compete with the likes of Microsoft's Surface Pro in the 2-in-1 space may be that kind of device. But based on the statements, it's also possible that this was once in development and no longer is.