It's well known you shouldn't use regex to parse html (actually, it's been said millon times), you should use a html parser instead.
On the other hand, if you want to use regex for this... you are pretty close, you have to use:
(?<Name>meta content=".*?")
Btw, if you want to grab the word Gizmo
you have to use capturing groups also withing your group Name
(?<Name>meta content="(.*?)")
Working demo
On the other hand, if you don't care about capturing meta content
and you just want to capture the content within content, you can use use:
content="(?<Name>.*?)"
Working demo 2