Not sure entirely what the question is, but I think you are asking if the Db2 developer extension in VSCode has the ability to edit tables via a GUI?

As far as I am aware it doesn't. You'd need to do it via writing/generating and running SQL.

I'm curious why you'd want to go down the rabbit whole as you say given that you already appear to have a tool that gives you the functionality you want? Datagrip is probably a larger and more full fledged product than any VSCode extension will ever be able to be and I'm sure your company is paying a pretty penny for it, so might as well use it if you can.