This is not a problem at all.  It's doing exactly what you are telling it to do. 
You have create a full join.  Every row in A will be joined to every row in B. 
In the example you gave, the first row of A contains the value of 0.00005644.  That row is being joined to every single row in B.
Scroll down, you will see A display 0.00017480, again joined to every row in B

What exactly are you trying to accomplish?