Way to quick move items

UPDATE: New features to the game including customizing augments. This feature requires the Item Modification Tables now. See Matthew Read's answer. The original answer that applies to the game as it was originally released, is still included here:

ORIGINAL:

It is a remnant from earlier item modification game mechanics Bioware was trying.

Currently the Item Modification Table has no special purpose. You can modify an already-modifiable item by Ctrl + Right Mouse Click-ing the item in your character or inventory window. You can still use the table to start this process if you want, but you don't need to.

EDIT: One on each starter planet is also used as the target of a "how to use item mods" intro quest.

You can ask your companion to sell your junk items for you. Press N to bring up your crew page, then press the button (on the right side of the active companion) to sell all junk items . Or, alternatively, right click on your companion's portrait and select "Sell Trash Items".

When you do this, your companion will leave for 60 seconds with the items, then return with credits. You can do this from anywhere, so assuming you don't need your active companion for a fight you can do other stuff while he's gone. When he returns, he'll be active again (no need to resummon). There are additive per-character Legacy perks, Legacy of Leadership I and II, that reduce this to 30 seconds and 5 seconds respectively.

Your companion will not sell items above "gray" level.