It is possible with some limitations.
An object such as an Excel workbook cannot span more a page break. If you need that kind of thing, you need to use a different paste format. getting the font sizes to match, though, is as simple as making sure the Excel object is scaled to 100% of the original size in both dimensions.
From what I know, if you paste an Excel range using 'paste link' and the HTML format, then click in the pasted table and choose Table Tools|Layout|Properties > Table > Options and set the left & right margins to 0, that will greatly assist getting the data to fit within the page margins. Mind you, if the data doesn't fit within the same page margins in Excel, you can't expect it to in Word. One thing to be aware of on this front is that Excel actually shortens the printed row heights. You can prove this by inserting a circle into an Excel worksheet, then printing the sheet. When you measure the printed circle, you'll find its height to be less than its width.