Character mapping in LEDControlMS.h

Dear forum,
I am having difficulty with understanding the character mapping in the library LEDControlMS.h
See code from the library file:

const static byte alphabetBitmap[41][6]={
{0x7E,0x81,0x81,0x81,0x7E,0x0}, //0
{0x0,0x0,0x4,0x82,0xFF,0x80}, //1
{0x0,0x0,0x0,0x0,0x0,0x0},// blank space
{0x0,0x0,0x90,0x0,0x0,0x0}, //:
{0x0,0x10,0x10,0x10,0x10,0x0},// -
{0x0,0x0,0x80,0x0,0x0,0x0},// .

I need to reduce the size and separation of the characters being displayed on MAX7219/UNO controlled matrices but cannot for the life of me understand how the code above relates to the characters so that I can edit properly - could anyone point me in the right direction please?

   {0x7E,0x81,0x81,0x81,0x7E,0x0}, //0
0x7E = 0b01111110
0x81 = 0b10000001
0x81 = 0b10000001
0x81 = 0b10000001
0x7E = 0b01111110
0x00 = 0b00000000

All your characters are 6 pixels wide and 8 pixels high. Turn that picture sideways. The ones represent where a pixel is on. The zeros represent where a pixel is off. As you can see, the ones form a nice 0.

Good luck building a font smaller than 6 by 8.

Thank you Paul, that is a great help - I just couldn't see it.
I have the matrices stacked vertically and so reducing from 8x6 to 6x8 will be ideal.

reducing from 8x6 to 6x8

What reduction do you expext from swapping the x and y axis?

With the font one direction, you can use 6 bytes/character, vs 8 bytes/character.

It's 6 bytes per character now... going to 8 is not a reduction, is it?

5 dots wide x 8 high (so 5 bytes of memory) work nice also for scrolling across a display:

Not a reduction as such but more a squishing and fattening of the characters so they fit better in a vertical run of 8x8 matrices.

So, for the character "2" for example instead of the current {0xE2,0x91,0x91,0x91,0x8E,0x0},//2
I shall use the squat version {0x0,0x1A,0x26,0x22,0x12,0x0},//2
Although by the looks of that it will be upside down although a little tinkering will present it correctly.

Oh my goodness, it took me so long to finally get it... I was just staring at it like "How? How does this make sense?"
And then finally that eureka moment...