I would really appreciate your advice. I have been asked to host a cocktail party for 50 people (an equal mix of men and women, heavy eaters). It will last from 5 pm to 9 pm. The proposed menu is as follows:

-150 crab stuffed deviled eggs
-150 servings of shrimp served on polenta rounds
-150 beef tenderloin sliders
-150 chicken satay skewers
-200 meatballs in sauce
-150 chicken salad on pita points
-150 mini spinach quiche
-150 bruschetta on crostini
- 4 large antipasto platters with marinated vegetables, cheeses, and cured meats
-100 individual Caesar salads

-100 cheesecake bites
-100 strawberry parfait shooters
-100 lemon parfait shooters
-100 chocolate petit fours
-2 large fruit trays with dip

As of now the current plan is four dedicated helpers (non party guests)- one person with me in the kitchen during the party, two people replenishing food/ keeping tables neat, and one person for beverage service. I have access to a full commercial kitchen.

Since this is a dinner party with a cocktail/hors d'oeuvres menu, you are aiming for about 1 1/2 pounds of food per person. As described, it looks like too much food, over-heavy on protein and sweet bites, very short on veggie bites.

-150 crab stuffed deviled eggs- 100 plenty, consider doing some without seafood for any allergic or vegetarians
-150 servings of shrimp served on polenta rounds- 100 plenty
-150 beef tenderloin sliders- 100 plenty
-150 chicken satay skewers- 100 plenty
-200 meatballs in sauce- you only need about 6 pounds cocktail size, a little less than 2 quarts sauce
-150 chicken salad on pita points- suggest you do at most chicken salad dip, 3 quarts with 3 pounds mixed crackers/pita, etc. I would do either the chicken skewers or the chicken salad, not both.

-150 mini spinach quiche- 80
-150 bruschetta on crostini- consider doing as dip/spread- you already have a lot of oven-needing items- no more than 100

- 4 large antipasto platters with marinated vegetables, cheeses, and cured meats??
You want about 6 pounds total cheeses, 1 gallon marinated veg, 2 quarts good olives, no more than 5 pounds cured meats, and frankly you don't really need the cured meats. If you do the crackers and the separated crostini above, you will have enough carb on the table
-100 individual Caesar salads- 50 plenty
If you want to add a colorful veg, consider tiny tomatoes skewered with tiny fresh mozzarella balls, and reduce the cheeses and other veggies accordingly
If you want to add a carb, 1 1/2 gallons of a really stunning pasta salad, or a unique potato salad like my Nepalese or Russian potato salad, would be a good choice.

-100 cheesecake bites
-100 strawberry parfait shooters
-100 lemon parfait shooters
-100 chocolate petit fours
50 of each max, maybe a few extra chocolate- this still allows 4 items per person, you will have leftover desserts

-2 large fruit trays with dip- 1/2 the deluxe tray for 100 on this site would be plenty

Even with these cut backs, expect you will have leftovers.