With GiMeSpace KMShare as the GOTD, and not to make slight of today's generous offer, wanted to quickly remind folks that the excellent Mouse Without Borders is free from Microsoft. It's available as both a standalone app, with 32 & 64-bit versions, and as a part of PowerToys, which is 64-bit only. Setup is easy -- it generates an ID, which you enter/confirm in the main copy of the software, the one installed on the PC/laptop you'll be working from. Then you set placement, e.g., set a PC, laptop, or tablet below your current PC, and when you drag the mouse below the bottom of your screen, it appears on that device, the keyboard functions on that device, and anything on the clipboard can be pasted on that device. You can have different arrangements, like all 4 [the max number allowed] in a row, one on each side of your PC etc. The implementation in PowerToys *I think* has a few more options.
microsoft[.]com/en-us/garage/wall-of-fame/mouse-without-borders/
learn.microsoft[.]com/en-us/windows/powertoys/