I have multiple activities and multiple categories, i need a form that allows entry of this data

@Niraj - Are you just trying to enter that information in a single record in a table ? 

You can either use a grid edit table or a many to many relationship using an intermediate table. So, what exactly are you trying to accomplish ?

if your set of questions/ crosstab is not going to change or expand over time you can bite the bullet and create 100 fields (10x10) and capture the values in a single form using alternate field labels. This method is not sustainable when the parameters of the cross-tab change.