When you add SharePoint 2010 Lists in the web part pages or wiki pages, it shows the “Add New Item” at the bottom of the list by default. In most cases, wiki pages are considered as a mashup views along with other contents and you don’t want “Add New Item” as one of the options.
The reason for this link is web part toolbar type property sets to the “Summary Toolbar” by default. Change this setting to the “Full Toolbar” or “No Toolbar” and you will be able to hide the “Add New Item” link.
Hope this helps