3tbsp should be enough. Remember, that if you bulk with the right foods, you probably already have enough good fats (olive oil , peanutbutter, salmon etc).
I have a question on this topic... Maybe I didn't understand what they were for, but I have been trying to cut for a while, and my diet is currently supplemented with 1 tbsp of nat pb each day and 2 tbsp of flax. Should I cut these out? Are they holding me back?