Why is the Total Current Account Balance of World positive and does it mean that the world has a net Trade Surplus?
Since we are not trading with aliens (yet), you are right in assuming the global account balance ought to be zero. Your data contradicts this because it is collected by numerous statistical agencies who differ in their capability and their methods. Examples for different outcomes could arise from:


different degrees of border control. The fact that an export is registered in country A does not mean it is registered as an import in country B.
different capabilities in processing and collecting data. In some development countries, a substantial share of the economy is informal, i.e. outside the scope of any authority. 
different statistical concepts applied.


There are datasets which try to overcome these difficulties by correcting them such that the global account balance is zero.