If your data is in a SharePoint List, you could just create a view on the List that is specifically of type DataSheet with the appropriate columns, go through the steps of adding a Web Part to your page (Site Actions-->Edit Page...) picking your SharePoint List which will use the default view initially, then choose Modify the Web Part from its dropdown menu and at the top of the new menu on the right side of the site choose your new DataSheet view you created.
Your users will now have all the functionality of the DataSheet view without having to go into the List and then picking the view. You'll have to watch out for real estate issues, especially if you have a lot of columns for users to view/edit. In that case you might want to use SP Desiner to add a new tablerow in the body that is colspan=2 to be the width of the left Web Part Zone AND the right Web Part Zone.
Hope that helps.