You could format the text file like a SSV (TSV or CSV as well), then instead of ReadAll()
I'd do something like this:
var file = reader.OpenTextFile(filePath, 1),
data = [], n;
while (!file.AtEndOfStream) {
data.push(file.ReadLine().split(';')); // or use some other "cell-separator"
}
Then the rest is a lot simpler and faster, if you've an empty table
element in your HTML:
<table id="table"></table>
Now just create rows and cells dynamically based on the data
array:
var table = document.getElementById('table'),
len = data.length,
r, row, c, cell;
for (r = 0; r < len; r++) {
row = table.insertRow(-1);
for (c = 0; c < data[r].lenght; r++) {
cell.row.insertCell(-1);
cell.innerHTML = data[r][c];
}
}