awk '
NR==1{split($0,h); next}
{print "For " $1; for(i=2;i<=NF;i++) printf "\t%s = %s\n", h[i], $i}
' file
For Dir01
Column1 = val1
Column2 = val2
Column3 = val3
Column4 = val4
For Dir01
Column1 = val5
Column2 = val6
Column3 = val7
Column4 = val8
For Dir01
Column1 = val9
Column2 = val10
Column3 = val11
Column4 = val12