Grab a a turkey sandwich to go with a dessert and a coke from Upper Crust and head to either Louis McKinney or Hawreluk to eat picnic-style.
Hit up Khazanna's lunch buffet for the black lentils.
rool: Or try Garage Burger for something more along the diner spectrum.
Hit up the Pyramids at Giza. Even if you don't like plants and don't go in, the views of downtown from around the pyramids are nice.
Eat outside at the tiny little Greek restaurant on 124th street that has about six tables in total (can't remember the name, help me out someone.)
Hit the mall because, well, it's a part of Edmonton and it has shaped a lot of perception (rightly or wrongly.) Not seeing it would be doing a disservice to one's understanding of the city in general.
If time and weather permit and you like outdoorsy stuff and can find someone to tag along, try a canoe rental for a float/paddle trip from Devon to Louis McKinney. It takes a full day, but it's fun. Pack a lunch and enjoy the day. Especially the views of the apartments along Jasper Avenue when you're almost done.