In my scope of work I have attended media events for new companies launching, for author introductions, for new products hitting the market, etc. It is almost always a sit down style presentation type event or a mix and mingle affair. The invitation, typically from the company/individual's media representative or the PR company handling that account, gives you reasonable detail to know the type of event it will be. Some will include dress code as business formal or the fact that you can bring along a guest/suggest another member of the media to invite. When in doubt, feel free to reply to your inviter and ask whatever question you have. Better to have that clarified than turn up at the event feeling unprepared.
A good pre-event strategy is to learn more about the 'why' of the event. If the invite had any additional information, be sure to read through and check for any clarifications you need. If you pitch stories then this gives you good information to send out feelers to a few editors. If you cover a specific beat then this gives you the initial information you need and you can have questions for the gaps that you'd like filled in. I also like to arrive a few minutes earlier so that gives me some time to get settled in, find my way in case I have never been to that specific venue before, have a word with the organizers, and maybe get to know a few other attendees as well.
At sit down style events, once the organizer announces the event is to commence, folks sit down and the presentation begins. Questions are reserved for the close of the presentation and people typically converse with other guests at their table. Sometimes the seating is pre-arranged. At more free flowing events, there is usually no format but to walk around and introduce yourself to folks, make connections, get a few words in with the stars of the evening and move on. In either case, there are usually name tags involved so remember to write you first name in bold caps so that people can read easily and stick or pin it on your right shoulder. That is typically the hand people shake and looking at your name close to your face rather than halfway down your breasts is professional. Carrying plenty of business cards on you is imperative. You never know who you meet and how they might be able to help you later or vice versa.
If food and drink are being served at the table then you have nothing to worry about. You eat what is served and thats that. If there are passed appetizers or a self-serve counter, don't feed yourself for the rest of the year from the food there! If beverages are involved then be careful to keep your clumsy side in check - the last thing you want is a spilled coffee on yourself or anybody else. If alcohol is involved, know your limits and don't make a fool of yourself at a professional event. Also do not be nasty to the serving staff, they are hosting an event and try to accommodate every request but they are human too and could be having a bad day. Always carry change on you even though you know food and drink at the event is complimentary. Your wait staff, drink pourer, table attendant, valet guy - all look forward to these events because it is their chance to make a little more than their hourly pay. I have made this mistake many times and felt like an idiot for it, so learn from my mistake - always have some change handy much as it is difficult to remember in this day and age where credit cards are the norm.
Be friendly with the other guests at your table and don't shock them with your thoughts on gun control or procreation. You are meeting them for the first time in all probability - those topics are for after your fifth meeting or even later. A good conversation topic is something related to the event, the city, the venue, the work you do, etc. In an open format you just have to be brave enough to go around introducing yourself or ask the organizer to get you started with someone they know and then you can hang on to that person for dear life!...NOT!
When the event is done, don't simply walk away. This is your time to leave a lasting impression so remember to thank the organizers, let them know if you have any follow-up questions, or how they can connect with you in the future. When you get back to work, remember to connect with everyone you met in one way or the other. I usually try to connect on Twitter/LinkedIn or both. If nothing else, I shoot them an email so that way they have my information and it shows that I took initiative to connect.
If you do end up writing about the product, event, individual, concept or whatever it is that the event is for, then always send your organizers a link or copy of that coverage. They will be ever so thankful - they are busy people and while it is their job to track all their media, a little help goes a long way in their good books, and who knows when it helps to be a name on that book!
What is your strategy to work a media meet and greet?