How to expand grid?

OK I think you mean you have "drawn lines" around all of your data? Are the cells below and to the right of your grid/data a faded blue/grey, compared tro a black border around your data?

If so, you can add borders to your new rows/columns using the button on the Home tab in the Font section. B (bold) I (italics) U (underline) and then a small square with a cross inside it...depending what cell you are in, it will either be mostly dotted with a solid bottom line or all solid lines. Highlight what you want borders around, click the drop-down arrow on that button and play around with the options offered

If hyou dont like what you get, use CTRL Z to undo what you just did.

Likewise, you can use that same button to remove all or some of the borders/grid lines

Hope this helps?