Were preparing a rather large dinner for 6 tomorrow to be served before the evening Steeler game; but looking for a simple snack for the game

You've already eaten a large dinner... Why not chilled red and green grapes, and bite sized cubes of cantaloupe, honeydew, and watermelon? Simple and fresh after a big meal.

Are ypu serving a "formal" dessert while at the dinner table? If not, then I'd suggest something sweet, and if so, I'd suggest holding it off until the game. People's dinners will have settled, they'll be more receptive to dessert, and likely enjoy it more. If you want it "nibbly", how about apple, pear and banana slice to dip into a really good caramel or dulce de leche sauce. Any other dessert would work, of course. Pie, cake, cookies, ice cream...

If it were me, that's what I'd do.

Grilling a smoked sausage, slicing it kind of thin, and serving with a course grained mustard is always a hit.

ChezSuzanne has a recipe on this site that might fit the bill
http://food52.com/recipes/15286_toffee_chex_party_mix

flavored popcorn is great. Also, chicken bites wrapped in bacon coated with brown sugar & chili powder.

Maybe Carmel corn? You can make it today and if YouTube like package in small cellophane bags for each of your guests.