Figuring I might not be the only one, thought I'd pass on word about Poetic's Indiegogo campaign. Poetic has been around for a long time - I've had folios from them going back to my 2012 Nexus 7 - and they deliver great 'bang for the buck'. They're campaining their new Explorer series for the Slate, which looks to have really good (for a tablet) impact/drop protection, built in screen protector, and - my favorite - an integrated slot to store the Pixel Pen.
It's $35, so was an easy decision.
Poetic Exporer case for Google Pixel Slate tablet