It is easier to see the imperfections in the 'flatness' of the bed when you have the bed closer to level. Here is the topography for a print I'm doing right now:

Mean of sampled points: 4.498123

Bed Height Topography:
--0.10869 +0.02526 +0.07123 --0.07925
--0.13349 +0.01203 +0.03584 +0.05469
--0.14705 --0.00054 +0.06495 +0.10530
--0.12225 +0.00277 +0.12745 +0.09174

Notice the first row starts negative, goes positive, and then goes back negative. And notice the second column. It starts positive, goes negative and comes back to positive.

Right now, your bed is tilted pretty hard from left to right. If you can get it more level, the imperfections will jump out at you. But with that said, looking down your 3rd, 4th and 5th column, the 4th row jumps up in value and then back down when it goes to the 5th row. But the 1st and 2nd column is the opposite. On the 4th row it jump down in value and then back up.