Best if you aim for Monday-Wednesday. These are the "quietest" days - not really quiet but more likely to find somewhere to sit. Don't aim for a weekend. These days it would have been a wasted journey. It is quite normal to share tables with other people. You just go in a tent and look for some space anywhere and ask to join ables. Bear in mind that some areas of tents are reserved areas.
At weekends, especially Saturdays, people queue up at 7am at each tents entrance to get in and get a table.
The Oktoberfest is getting worse every year. I've been going for 20years now. Myself and the wife often used to go to the Wies'n on a Saturday (if nice weather) and never had a problem walking into a tent and finding a spot (everybody shares). Normally only an issue if the weather is bad as everybody goes into the tents and then the tents are locked shut due to overfilling. Last year despite blistering sunshine ALL the tents were locked by 1pm.
There are 14 drinking establishments - but ~ 10 main larger Brewery tents.
examples of sizes
The Schutzenzelt only seats ~ 4500
Hacker ~ 6900
Hofbräu ~ 6900
Reservations are only made directly tot he Tent owners and these reservations generally open in March.
You can only reserve entire tables. Tables generally seat 10 (there are sometimes other sizes but they are in the minority). You do NOT have to have 10 people to book a table. You just pay for 10 peoples worth of Beer and chickens. This is how ALL the tents book their tables (except for the Hippodrome)
You always pay for 2 Beers + 1chicken multiplied by the table size (normally 10). Normally ~ €300
Think about the unscrupulous people out there who offer individual seats at $300 a time
Bear in mind my Wife ON HER OWN books 5 whole tables at the Löwenbräu every year. Löwenbräu don't care how many people we are they just want her to pay the 5 x 10(peoples worth).
The tables are infact more comfy with 8 people on them.
You will NOT get a reservation for Friday night or the Weekend. They are DEAD MANS SHOES. My friend has had 6 Tables at the Armbrust for the last Saturday for 12 years now.The problem for any new customers is that the Tent's owners take care of their regular customers first. Every year they send out letters to their "Stammkunden" like my wife and friend asking them if they would like to rebook. Once they have taken care of all these customers any remaining tables are then made available for general sale. You can often only apply by fax then basically it is a lottery. You sit and wait.
If you are looking at staying outside of Munich then you can take advantage of a transport ticket called the Bayern Ticket.
You can buy this group ticket for up to 5 people (€22 for 1 person up to €38 for 5 people).
Gives you unlimited use of ALL Regional public transport in Bavaria. Includes ALL Regional trains,Regional buses and ALL city transport (e.g. in Munich or Augsburg). Valid from 9am weekdays (midnight weekends) until 3am the following morning.
The faster IC, ICE, EC and Railjet are excluded. To be honest on some routes there are very few or no IC services etc
Regional trains also include BOB trains that service Bad Tölz and Tegernsee
Consider that Augsburg is only ~ 45mins from Munich on Regional trains and there are a couple every hour.
Bad Tölz ~ 50mins - train every hour
Consider that Munich-Salzburg Regional trains (2hrs) are included (run every hour) you can also use the tickets for other things
Garmisch 1h30 (every hour)
For general info bahn.de/i/…laender-ticket.shtml and click on Bayern.
NOTE: Ignore the pricing as it changes from tomorrow. Here is the blurb in German -the pricing is show "per Personen"
To see Regional services use http://www.bahn.de/i/view/GBR/en/index.shtml and tick the box "Local Transport" - just ignore the individual single ticket prices.