Can Android phones/tablets access W-Fi network drives? There are many WLAN routers currently available which have a USB port to connect external HDDs. These are than easily available on Windows machines directly in Windows Explorer, they look like common network drives.

If I used an Android-based smartphone or a tablet which support WLAN, would it be possible to access these network drives somehow? I'm entertaining the idea of getting a tablet, and it's important to know if I can access a larger storage than what would be available locally via an SD card (if such a slot even would be present on a particular specimen).
I believe most of these routers mount your drive as a network samba share (like windows file sharing), which android phones can access with apps, like ESFilexplorer or AndSMB. They can stream off it or download files to SD card.