My "rumor table" is probably a bit misnamed. It's not just rumors. In my current game, I mix three things into my "Rumor" tables:
Rumors, events, and random encounters.
Here is what I mean by each.
Straight up heresay, bits of legends, feedback on previous delves, actionable clues, etc. are the mainstay of the rumor table. Here are some rumors that showed up in my game:
"Those six-fingered vampires are supposedly part-elven, so you can speak to them in elvish."
"Ain’t no one ever cracked the main doors of Felltower, and that’s a fact."
As always, these are a mix of true, not true, and in between. For many, I don't even know if they're true or not, but they might become one or the other in play.
Some of the "rumor" rolls actually turn up events. Until someone rolls them, the stated event they hear news about hasn't occured. Roll up "I hear there is a new potion shop in town!" and there is a new potion shop in town. Until it's rolled, there isn't.
For example, here are two "rumors" that were actually "events."
"A family of dwarven armourers has made a deal with the city’s smiths, so dwarven gear will be much more readily available."
"There are snakemen warriors visiting from the deserts of Morthand."
For both of those, once I rolled them the thing spoken about happened. Dwarven gear bumped up a level in availability. My snakeman minis had been finished getting painted and were now available as NPC hirelings with No Legs (Slithers) on their Traits list (which didn't stop them from becoming a giant army of snakemen at war with the orcs).
Some of the "rumors" are actual encounters for a given PC or PCs (if multiple people make the same roll, I worked that in.) Someone selling a map or an object, a recurring minor NPC with a rumor, a chance to sell something not normally salable, etc. will be on the rumor table instead of just a town encounter. For the encounters, reaction rolls matter - I'll jack up the price if the angry outlander gets the offer, maybe lower it if the desperate gnome meets the gnome PC, an so on. It's really an encounter, but boiled down to just the nugget that affects the dungeon delve or shows the effect of a dungeon delve.
Here is one that spawned its own post:
"Hey, I'll trade you this piece of gold I got - I found it under Felltower almost fifty years back. (Offers to trade 1 gp - with a ape head one one side with a crown or something on its head, and weird writing on the back - with Gift of Tongues reads "All Hail Gorillicus the Great") for 2 gp."
You can see the embedded self-instructions I put in, in parenthesis.
I have occasionally given blanket news items, but even then I prefer to direct it to one person. When Black Jans the Enchanter first showed up in Stericksburg, Nakar the Unseen (a now-deceased PC) received a letter announcing it. Actually, a physically printed letter I gave to the player. I didn't include that on the table, but nowadays that's exactly what I would do.
I do these this way for a few reasons. One is so that socially active PCs get more of these results - better Carousing skill rolls and so on pay off. etc.
Another is to keep the town feeling alive and vibrant. "I heard" becomes "this happened" or "I did (such-and-such)." It opens the world in a way that "roll three rumors, and then this encounter happens!" It also means that news and changes in town tend to be more noticeable. Instead of the GM handing them out to the group as a whole, it's the GM (me) telling it to a single specific play, who now owns that news. The rest of the table hears it (or doesn't, because they're not paying attention for whatever reason) but that PC is now connected to the story or the event. "Some guy in town is selling a map, does anyone in the party do something about this? is nice, but compare that to "Some guy offers YOU a map right now for beer money. Take it or leave it."
I highly recommend this - use it just as you would mix "wandering damage" into your wandering monsters. Try mixing in events and two-bit encounters into your rumors and carousing. It's fun all around, and makes rumor rolls more than just stuff you heard but things you get to do . . . or in a meta-game sense, caused.