I want to reduce the long pause between two songs.
Yes, after you have added a song to a slide show, click on that song on the timeline (under where the image thumbnails appear). In the middle on the right side is the Properties panel. You will see the properties for this song. This includes a little time line of the song. On the right and left of this timeline are Start and Endpoints. If you drag the End point to the left, this will shorten the song by causing it the end early. If you move Start point to the right, it will also shorten the song, but by causing the song to start late (thus cutting of material from the beginning of the song).
(screen shot from Elements 11, but you should have similar controls in Elements 8)