Brien - what the deal is anyone can reserve a table of 10 (but it has to be the full table) and all the seats at that particular table are pre-assigned to those 10 people. These tables are marked off and "reserved" by table number (1,2,15 whatever) and when you pick up your ticket, you'll get your table assignment.

If you don't have reserved seating, there is plenty of seating available (also tables of 10) - so when you enter the banquet room, I THINK you simply find a seat at one of the non-reserved tables.
It's a good way to meet people because you'll undoubtedly be dining with others... - but the open seating has always been in the back of the room (it's not like it's Siberia or anything) and the reserved tables are up front - closer to the podium/ speaker.

The problem with reserved seating is one person must pay for the entire table upfront. Some VERY NICE PEOPLE actually buy everyone's dinners (I'm not one of them ) - but many (including the people I've joined in the past) reserve a table (and the attendees reimburse them) to simply get banquet seating out of the way.

What the banquet committee dosn't want to do is shift through hundreds of reservations and match people up as they go along... (I don't blame them) So to secure reserved seating (I think it IS much better which is why I'm trying to fill a table) - they want all the money at once and the names of those who those tickets cover.