Is there a program like (Download Accelator) that works on Kubuntu. So if the download was paused or interupted, it can continue from where it stopped?

There's a difference between a download manager and a download accelerator. A download accelerator will start more than one session simultaniously from the same server. This might work sometimes. I've never used it.
I usuall use wget for larger downloads. It can resume, and a million more things. It's command line but really easy to use. It's just "$ wget [url]" And it saves to the directory that you're currently in. To resume, I think it's "wget -c [url]"
I just stumbled across "gwget" googling. You might want to give that a try.
The sun download manager is also good.