From 4dots Software:
4dots Copy Text Contents is a small shell extension that extends the right click menu of Windows Explorer and allows you to copy directly the contents of text files to the clipboard. This is useful when you just need to quickly copy to the clipboard the contents,for example, of source code files or other text files, in order to paste them elsewhere. One or multiple files can be selected and entire folders. You can use the default encoding to read the files or you can specify the encoding explicitly. If multiple files are selected you can optionally add file headers to the text. Moreover, when selecting a folder you have the option to include also its subfolders files. Both Windows 32bit and 64bit are supported.