If you use a tablet plan on a phone, you run the risk of being charged for each minute of talk you use or each sms you send.  If you can avoid texting and calling, then yes you can use the tablet plan as a data only plan.

In the fine print for that plan it also states:
“A tablet plan may only be used with a tablet device, and requires that you maintain a Koodo mobile phone plan. If these conditions are not met, Koodo may terminate your tablet plan in accordance with the Service Terms.”
https://www.koodomobile.com/en/tablet-rate-plans

Allan,
Thanks for getting into the details.  Good to know.