Were there many Gamgees?

[The Saucepan Man]

Neither Hamfast nor Sam were present at the Long-Expected Party as it is presented in the book. The guests in the tent were those invited to the special family dinner-party, and the numbers were restricted to twelve dozen. They were:

selected from all the families to which Bilbo and Frodo were related, with the addition of a few special unrelated friends (such as Gandalf).

I suspect, therefore, that the Gamgees were not as closely related to the Bagginses as those families that were present and that neither Hamfast nor Sam counted as "special unrelated friends", the relationship being (as has been mentioned) one of master and servant (albeit one which involved a great deal of mutual respect).

As Eomer has pointed out, the film does not play on the class divide and so the Gamgees (or Sam at least) were present at the party. The reason that they are not mentioned in Bilbo's speech is, no doubt, because they lifted the speech straight from the book (where no Gamgees were present).