Android tablet question

[Phil]

Thank you for reading this.

I received a Chinese tablet in the mail yesterday, and as is often the 
case, without a manual. Although I have never seen a tablet before this 
(I live in a remote area) I was able to get it going with the help of 
Google. Anyway, to my question.

I'd like to connect my tablet to other computers on my WiFi network. I 
can ping the Android device from all the other computers but the tablet 
(using ES File Explorer) can only see one computer. That computer dual 
boots Vista and Kububtu. All Vista Directories are visible but only half 
a dozen, or so, printer related directories are visible under Kubuntu. 
My Xubuntu laptop is not visible to the tablet at all, possibly because 
I don't have a printer associated with that laptop. Yet I can connect 
the laptops to each other via SSH. My raspberry pi is not visible to the 
tablet either.

So, is there a file sharing option that I have to turn on within the 
Ubuntu laptops or is there more to it than that? I don't think this is 
an Android specific question but if it is I'll search for an Android forum.

-- 
Regards,
Phil