When my board games group come over, we move my drop leaf kitchen table to the living room where there is more space, and expand it to full size, which is about 780mm x 1200mm. We get a game out and start to set up...

At that point, the two people on the short edges start to complain that they don't have enough room, their stuff overhangs the table etc etc.

3 solutions have occurred to me so far:

1. Get new friends. Possible but takes time and there's no guarantee that new friends won't also complain
2. Buy a new table. I've looked at UK based shops for drop leaf tables but the ones that give more space won't fit through doors
3. Make a table topper to sit on top of the kitchen table and provide a larger surface

Number 3 is clearly the one I've brought here because although it's a grand idea I'm not sure how to go about it.

Material

It's games night, there's drinks involved. Something that doesn't mind a bit of water seems like an idea, maybe moisture resistant MDF? Not too expensive, easy to get hold of. Thickness 18mm so there's no flex?

Size

Not too big but clearly needs to be bigger than the table it's covering, probably 1000mm x 1220mm

Top

I was thinking about tacking felt to the top for a proper gaming surface, is that sensible or overkill

Fixing

The tricky bit, I don't want it to slide about on top of the table when we're playing and someone leans on it. Equally the kitchen table spends 99% of it's time being just that so I don't want to drill into it on the top. Will non-slip mat be enough or do I need clamps/hooks/bolts?

Any ideas from the hive mind gratefully received!