i have category products and something size position for category how i can set

[easy.proger]

how i can set all sizes for my products in something category ? i can set every product manualy sizes but its long (

exampl
i have category named "underwear"
and for this category sizes
0
1
2
etc ...
i add product in this category "product1"
and i want set all sizes for this product
how i can do this automaticaly ?

manualy i can add for product1 custom fields size in set manualy size but its to long (((