golflua, 54 49 characters

~@i=1,9~@j=1,i I.w(S.q(i.."x%d=%-3d",j,i*j))$w()$

Sample run:

bash-4.3$ golflua -e '~@i=1,9~@j=1,i I.w(S.q(i.."x%d=%-3d",j,i*j))$w()$'
1x1=1  
2x1=2  2x2=4  
3x1=3  3x2=6  3x3=9  
4x1=4  4x2=8  4x3=12 4x4=16 
5x1=5  5x2=10 5x3=15 5x4=20 5x5=25 
6x1=6  6x2=12 6x3=18 6x4=24 6x5=30 6x6=36 
7x1=7  7x2=14 7x3=21 7x4=28 7x5=35 7x6=42 7x7=49 
8x1=8  8x2=16 8x3=24 8x4=32 8x5=40 8x6=48 8x7=56 8x8=64 
9x1=9  9x2=18 9x3=27 9x4=36 9x5=45 9x6=54 9x7=63 9x8=72 9x9=81