xlsxから( http://blog.pamelafox.org/2013/06/exporting-google-spreadsheet-as-json.html )みたいなjsonを吐く。

xlsx2tables.js

var xlsx = require('xlsx');
var _ = require('underscore');

var file = 'test.xlsx';

function parsePos(x) { // "AB" => 26*1 + 1*2 => 28
	var str = x.toUpperCase();
	var ret = 0;
	for(var i=0,len=str.length; i<len; i++) {
		ret += Math.pow(26,(len - i -1)) * (str.charCodeAt(i)-64);
	}
	return ret;
}
function convPos(pos) { // "B3" => {x:2, y:3}
	return {
		x: parsePos( pos.match(/^[a-zA-Z]+/)[0] ),
		y: parseInt( pos.match(/[^a-zA-Z]+$/)[0] )
	};
}
function xlsx2matrixs(xlsx_path) { // xlsxからシートごとに2次元配列
	var ss = xlsx.readFile(xlsx_path);
	var ret = {};
	_.each( ss.SheetNames, function(sheet_name) {
		var sheet = ss.Sheets[sheet_name];
		var range = convPos( sheet['!ref'].match(/[a-zA-Z0-9]+$/)[0] ); // !ref: "A1:C6"
		var matrix = new Array( range.y );
		_.map( _.range(0, range.y), function(y) {
			matrix[y] = new Array( range.x );
		});
		//console.log(matrix);
		//console.log(range);
		_.each( sheet, function(val,key) {
			if(key[0] === '!') {} else {
				var pos = convPos(key);
				matrix[pos.y-1][pos.x-1] = val.v;
			}
		});
		ret[sheet_name] = matrix;
	});
	return ret;
}
function matrix2table(matrix) { // ひとつのmatrixの1行目をヘッダとみなしてテーブルに。
	var cols = matrix[0];
	return _.map( _.range(1, matrix.length), function(x) {
		var row = {};
		_.each(cols, function(el,it,list) {
			row[el] = matrix[x][it];
		});
		return row;
	});
}
function xlsx2tables(xlsx_path) {
	var ret = {};
	_.each(
		xlsx2matrixs(xlsx_path),
		function(val,key,list){
			ret[key] = matrix2table(val)
		}
	);
	return ret;
}
console.log(
	JSON.stringify(
		xlsx2tables(file)
	)
);