Where to stop for lunch on way from Venice to Tuscany

Are you looking for something near the highway or in a city? If a city, beware of ZTLs.

Something in the area of Bologna, Modena or Parma would be great.

Any Autogrill restaurant in a service area along the autostrada. There is nothing picturesque between Venice and Bologna. South of Bologna you go through some impressive mountains.

Second Robertos' recommendation, food is good and a great place to stock up on wine, breads, cheeses and meats for your stay in Tuscany.

I can't do you picturesque either until you get in the mountains south of Bologna. Maybe something in Bologna?

Had the same problem and found the little town of Sasso Marconi. Not real picturesque but okay. Key was the food. Osteria dei Sani in the heart of the small old town area was great. Only Local folks, local prices.
Way off the tourist beaten path.

If you go to Sasso Marconi you should visit Guglielmo Marconi's house and museum. That's where the inventor of the radio was born.