There are five in the last three columns of Industrial Age that you can skip:
1. Reconnaissance
2. Victorian Houses
3. Law and Order
4. Ballistics
5. Breech Loading
Numbers 4 and 5 are dead ends at the end of the Industrial Age tech tree. Numbers 2 and 3 only lead to those two, and number 1 only leads to number 2. None of them provide expansions. I don't remember if any of them unlock buildings that are needed for Story quests, although Police Station (a cultural building unlocked by Law and Order) is tickling the back of my brain on that. EDIT: There is a Story quest called "Fighting Crime" that requires either building 2 Police Stations or deleting 8 Musketeers, so at least there's another option.