I've never used rumour tables in my games, and I'm now realising that I probably should. They always seemed a bit dry and artificial to me, but I think they're important for fleshing out the world and giving players more options than just following the first plot hook that the GM introduces.
To make them feel less arbitrary, here's a micro-system that gives players a little bit of control over the rumours they get:
Each rumour has one word HIGHLIGHTED in its text. When PCs are in town, the GM reads out all the highlighted words and each player picks one. Their character hears that rumour. When the PCs return from an expedition, replace the known rumours with new ones and let the players pick again.
Example for my upcoming Mausritter game:
1. The frog village down the RIVER has not been heard from in several months.
2. Monks at the abbey of St. Ninian dug up a mysterious STATUE in their vegetable garden.
3. The ROSE Tombs contain strange treasures of mice who came before.
4. A vicious CORGI has been seen roaming the wilderland.
5. The dreaded cat, Tom-o'-the-Mount, has AWAKENED and left his underground lair.
6. The rat folk are mustering an army in the LAVENDER Hills.
Hopefully this will make the rumour process more interactive, give more hints about the world, and make players excited to return home and refresh the rumours. My gut instinct is that it's better to pick words that are distinctive but not necessarily the most informative. For the table above, FROG, ABBEY, TOMBS, CORGI, CAT and RAT might give the players more control, but it would make the process feel too much like just picking from a menu.
This system is not playtested, so I would be interested to hear feedback about it.