First and most important, an appetizer table, and here is why:

"A self-catered buffet is a real challenge to the organizers, and things don't always come together as smoothly as hoped. By planning and setting up an appetizer area or "nibble table" which is ready when the guests begin to arrive, the cooks and servers have time to complete the arrangement of the dinner buffet. This is especially critical if there are children among the guests, or there is a wait before dinner, as at a wedding reception.

This does not have to be complicated. Three items, plus a punch, or two if one is alcoholic, are sufficient. Typically, include a fruit tray, a cheese tray and an attractive dip or spread; or you can go with a dinner theme such as TexMex with chips, salsas, Texas caviar and guacamole; Italian with bruschetta or antipasto; maybe shrimps or other cold seafood, if budget permits.

In this menu, something headed toward a classic antipasto would be excellent. About 4-6 "bites" per person.

Each appetizer service area graciously accommodates about 100 guests."

You should have plenty of pasta and sauce. However, there is no accommodation for any non-meat eaters, and with 150 people, there will be some. Strongly suggest you add about 20 pounds chopped broccoli, and leave some of the alfredo sauce plain; also about 25 pounds roasted veg (onions, squashes, tomatoes, etc) these can be done ahead and served room temp, Italian style, if oven space is an issue.

Increase the bread to 15-18 pounds. Dipping oil on the tables? About a gallon. The Parm cheese will work best if set on the tables, also.

You need to add a few gallons unsweetened tea. Also dinner level coffee, see the beverage planning page, is a very good idea with dessert.