Amazin Billiard in Malden is pretty close, don't know what they have on Wed nights, they have 8 very well done tables, with another 4(?) 3 Cushion tables as well. They are a membership room but if you call and ask they may let you in just for hourly fee.
40 Faulkner St. Malden, Mass 02148781.605.2389
Ayer is further, and has a Masters league on Wed night (I'll be there), so will have a decent number of B players there. There is also a women's league Wed night but should be a few free tables. Not much gambling though, some guys play 3-6-9 for a few dollars but that's in, never seen anyone play for 5-10 a game or anything by the set.
Ayer is a 45 min drive, but if Malden is filled you have a better chance of getting a table there. Malden is 25 min drive.