erik-challenge.js

var data = [['B1','B2','B3'],[1,2,3],[4,5,6],[7,8,9]];

// this would normally be provided by some sort of functional lib (or in a real functional language)
function zipObject(keys, vals) {
    var zip = {};
    keys.forEach(function(k,i) {zip[k] = vals[i];});
    return zip;
}

function generateWantedData(columnNames, ...data) {
    // map over data, zipObject for each column name
    return data.map(function(valueArray) {
        return zipObject(columnNames, valueArray);
    });
}

console.log(generateWantedData(data[0], data.slice(1, data.length)));

// var wantedData = [{'B1':1,'B2':2,'B3':3},{'B1':4,'B2':5,'B3':6}, {'B1':7,'B2':8,'B3':9}];