I bought a plate set that was said to be for a 6" Rotary Table, but I
haven't found a reference to the PYH brand.
I expect that it is an import generic/house brand like SPI is for Enco.

I thought there might be a possibility that these would fit a 6" Phase II
RT, but they don't.

So here are the dimensions and hole pattern numbers for a RCM archive
reference:

3 plates marked A - B - C

Diameter: ~4" 100mm

Center Hole Size: 0.827" 21mm

Attachment holes: 3 hole circle ~1.263" ~32mm
Center-Center 1.09" 27.67mm

Hole patterns:

(A) 15, 16, 17, 18, 19, 20

(B) 21, 23, 27, 29, 31, 33

(C) 37, 39, 41, 43, 47, 49

The arm for the indexing pin appears to fit a handwheel shaft with two
flats, not a keyed shaft like the Phase II has.
The mounting slot appears to fit across ~3/8" or 10mm handwheel shaft flats.

The set looks the same as the Enco/MSC 6" SPI import brand plate set.

PYH TDM1F/6 6" Rotary Table Dividing Plate Set
Made in Taiwan

TDM1F/6
Cat # 51-225-1
Model # 05082466

Stock/SKU label number 87405082466 070 (looks like an Enco or maybe MSC
label)