The 2 tables that requires the absolute least amount of Mastery Points (133) are Secrets of the Deep
& El Dorado
but since these might neither be the easiest to all or owned by all, you can find out which one is the lowest, of those you own, by selecting any table from the selection screen to go to the start menu of that table & in the middle of the screen there'll be a section called "Table Mastery
" enter this & you'll see ALL Collectibles available for all the tables
,some tables, as the 2 mentioned above, only have 2 Collectibles while 2 of the Star Wars Tables have a maximum of 7 Collectibles.
However the Mastery points are very unique from table to table, so more collectibles doesn't necessarily mean more Mastery Points needed & the Maximum needed is the full 200 so at the end of the day I think it depends on which table you feel you do best on but still a lower Mastery Points needed the easier it should be.
& with that I'll wish you all the best of luck
EDIT: After trying different tables, I actually do think that the easiest table have to be The Sorcherer's Lair
simply because it's easier to upgrade the different stuff like bumpers,combos & skillshots not to mention that some tables don't even have them all e.g Combos aren't possible to do on all tables & so can't be upgraded (oh & a tip for skillshot on Sorcherer's Lair is; pull back the launcher with the Right Stick until just before the 2nd pibe starts steaming & release, a few tries & you'll get it every time
Finally the achievement, which also rewards you some Mastery Points, 20 to be exact,aren't that hard either (to those who remember the Spiders achievement on FX2, they've made it MUCH easier, I weren't able to unlock it on FX2 but it popped on first try here on FX3)
As for progress needed for the achievement, I had only leveled a few of the upgrades to max. (lvl.10) & most where at lvl.6-7 & only 1 of 3 wizard powers had been leveled up (to lvl.4) while the 2 others had just been unlocked when I popped this achievement.
So while other tables might require less points they are easier to earn on the Sorcherer's Lair so again, best of luck my fellow cheevo hunters