Players can't make rollable tables, only the GM can. They really can't be shared. When you copy a game, they can copy that way, or the transmogrifier (pro subscription perk) can move them from one game to another. This is one reason I build a base game and copy that when I start a new campaign or run a one shot. As far as what is useful? 1. Some people have trouble coming up with names. So I have come up with a fairly extensive name generator... I have 2 different macros set up, one for to generate female leaning names, and one for male. For each language, I have a table for: female name, male name, and family name. I have those 3 for a bunch of names (almost all have 90+ entries making repeats rare) in the following languages and styles: Greek, Roman, English, French, Italian, Norse, Latinized Swiss, and Gaelic. Following that, there is a multi-part "savage" name generator for orcs/goblins and such, as well as another 3 part set for "pastoral" names (think hobbit names from the shire and you will be close). I also have a table that prints out "epithets" like "the wise", or "the cruel" in case someone wants to have something like that to be known by. I make this available to people when they are creating a character. Not because I expect them to just take exactly what is rolled for a certain language, but to mix and match or just use one of the results as inspiration. Obviously, I use this to reduce straining my brain when naming npcs. I tend to run lower combat, higher npc interaction games, so names can be pretty important. One click will nearly fill chat from top to bottom with male or female (depending on the button press) name ideas. 2. How is the camping today? I generally like to have an idea what the weather is doing in my games. I didn't do anything as extensive as the the names. For one thing, I didn't want to be too specific, because then you need a different set of tables for each regional climate. I use 4 tables, with one macro that calls them all to print out in chat. Wind direction (related to prevailing wind direction), temperature variance (compared to what would be normal for the area), wind speed, and overall weather (overcast, clear, precipitation, etc.) are all I have tables for. I do keep a calendar and try to keep a month or so ahead of the party so I know whether it is a beautiful day for flying or not. 3. Random encounters, anyone? To be honest, I thought I would use these more than I do. I tend to prefer encounters that have bearing on the characters or what is going on specifically in the area rather than truly random stuff. People who run a more random generated exploration type game would get a lot more use out of these than I currently do. 4. Silly stuff. I made 3 tables that work together to generate insults. I have thought about making a single one for more complicated insults/negative comments than can be generated by the multiple table method. Why do this? Well, there was a big fight with a demon, and I thought it would be fun if it shouted an insult with each attack. It isn't something I plan on using a lot, but for occasional use, it seemed to go over well. The demon got away in the end, so I need to change it up a little for the next time they meet. I know one DM who is setting up a random table for bardic performance (oratory in pathfinder) checks. Just random little sayings, but sprinkled among them are joke sayings that will only have meaning to those of us that have played together previously. 5. Who are you? Similar to the names, I have a couple rollable tables for disposition and pet peeves (likes or dislikes). While I encourage people to use these in character generation if they don't have an idea in their mind about who their character is, I primarily use this to help me avoid having too many 2 dimensional npcs. I know there are quite a few people that don't like the way rollable tables work on Roll20, but I get a lot of use out of them.