First, a little context. What you are seeing is what is represented on the messaging channel of joinmarket (currently it's an IRC channel). There are two different roles for entities: "Maker" and "Taker". You're seeing here the published offers of the "Makers", who sit in the "pit" (like a trading pit) waiting to do coinjoins with whoever comes along and matches up with certain conditions (see below). So if you see "219 orders found by 53 counterparties" it means 53 different joinmarket bots are active on the joinmarket trading pit, waiting to do deals, and some of them are publishing multiple orders with different conditions under which they're prepared to do a transaction.
The amount of data is a bit mind-numbing. One interesting data point that's easy to see is: click the "maximum" column once or twice to see the orders listed by size. E.g.: if you see a 220 btc offer as the highest one, that means there's one bot that's offering to do coinjoins at a maximum size of 220 bitcoins.
It also may be of interest to look at the "Size distribution" and "Depth" pages, which show some of the orderbook data graphically.
Each order published by a bot is either "relorder" (relative) or "absorder" (absolute) currently. The meaning is simple: the bot either charges a flat rate in satoshis to do a join, or charges a percentage of the amount of the join. As you can see, most of the fees are very low but there is usually a pretty wide range.
This is the IRC nick of the bot; in most cases it's a random string, created by the joinmarket code by default. It isn't intended to be a persistent identity, and usually it will change whenever a bot reconnects. Some people choose fixed names, but it doesn't matter much.
This is a number assigned to each order for one bot; as you can see from the top line, each bot can offer many different "orders" (really, offers), so this helps track them. There isn't actually any advantage in creating tons of these 'orders', since the code of the Taker doesn't give preference to bots with multiple orders. However multiple orders gives fine-grained control, e.g. offering a different price for different BTC amounts in the join.
This is what we call the "coinjoin fee" or "cjfee" for short. This is the amount the Maker bot requests from the Taker bot to take part in the join.
Miner fee contribution
This offsets the former amount effectively; so if a Maker requests 10k satoshis but offers 1k satoshi mining fee contribution, the Taker will effectively pay 9k to that Maker, and pay the full mining fee herself (just another, probably simpler way of looking at it).
The minimum size of the join allowable for this