To transfer data from USB to Android tablet is very very easy. But if you do not know its correct steps, you will waste your diamond time. For saving your diamond time, I have made this video for teaching the correct and simple steps.
Start your Tablet. I am using HCL, tablet, you may use any other.
Attach your USB, USB may your pan drive or mobile drive whose data, you want to save in your android tablet.
Press File manager in the home page of tablet.
Press the file for some movement to whom you want to transfer from USB to tablet.
You will see pop up copy option.
Press on the copy option.
Go to local or your tablet hard drive.
Press in any file.
You will see paste option. Press on paste. Your file will be transferred from USB to tablet. Now, leave your USB and enjoy to open file by opening it through related apps.