Microsoft is offering a new terminal application for Windows 10 (available in the May 2019 update from the Windows Store). It supports tabs, and can co-exist in tabs alongside Windows command prompt, WSL bash and PowerShell sessions. A preview edition is available now.

Unlike PuTTY, it supports tabs, Unicode, GPU rendering and themes. What isn't clear is if it contains ssh support built-in, or if you would have to open a bash shell in WSL and then ssh from there.

Some more information here:

Has anyone tried this to log into Ubuntu/Linux systems from Windows, or plan on trying it?