SharePoint 2010: How to upload big files use client object model

Можно делать вот так:

using (var clientContext = new ClientContext("http://myserver"))
{
    using (FileStream fs = new FileStream(@"C:\myfile.doc", FileMode.Open))
    {
         File.SaveBinaryDirect(clientContext, "ce/SuperDocLib/myfile.doc", fs, false);
    }
}

Нашел тут.