after all my searching Here goes the Answer it's just as simple as that.
VB.Net :
Append the "& vbCrLf &" to the string where you want to break the line to Display Multiline Text in Textblock and Label controls.
Example :
"RTY"& vbCrLf &"EER"& vbCrLf &"RRR"& vbCrLf &"SFG
Result :
RTY
EER
RRR
SFG