follow these steps:
Step 1: Connect your iPad with PC using data cable that comes with iPad. Download and install iTunes, Run iTunes and select your device from left panel under "Devices" section.
Step 2: Click on Photos tab, Check the "Sync Photos from" checkbox and select "Choose Folder…" option from drop-down menu. Locate the pictures folder from computer and hit "Select Folder" button.
Step 3: When folder listed in iTunes, select all pictures that you want to copy in iPad and hit Sync/Apply button from bottom right corner.