In the K40, TMR0 functions different than it did in previous devices.
In 8-bit mode TMR0H becomes a programmable period register (similar to how TMR2 works).

It looks like you're running at 16MHz.
If you have the timer set for Fosc/4 mode T0CS<2:0> = 010, then at 16MHz TMR0 counts 250ns

You want to count a total of 10ms/250ns = 40000

The postscaler settings are 1:1 to 1:16, and the 8-bit count = 1 to 256 (since it reloads on the next count)
So the largest count x postscaler value = 16x256 = 4096
You have to use a prescaler that gets you < 4096

Pick prescaler 1:32 = 40000/32 = 1250, which is < 4096
Then set count=125 with a 1:10 postscaler -> 1250

So, to get a 10ms TMR0 8-bit setting try this:
- set Fosc/4 mode T0CS<2:0> = 010
- set 8-bit mode T016BIT = 0
- set prescaler to 1:32 T0CKPS<3:0> = 0101
- set postscaler to 1:10 T0OUTPS<3:0> = 1001
- set period count = 125 (load TMR0H with 125-1=124)