Concatenate
The concatenate function in Excel is very useful for generating repetitive wiki code.
Tables
Two Columns
=concatenate("||",a1,"||",b1,"||")
Three Columns
=concatenate("||",a1,"||",b1,"||",c1,"||")
Lots of Columns
=concatenate("||",a1,"||",b1,"||",c1,"||",d1,"||",e1,"||",f1,"||",g1,"||",h1,"||",i1,"||",j1,"||",k1,"||",l1,"||")