The following is a repost from another thread. The last paragraph should explain how/why you are getting a new clip (with an incremented #) in the video file bin.
ADD a FILE, which will then appear under the VIDEO tab in the media area.
Drag the preview window scrubber (the red line that moves to the right as the video plays) to the desired IN point and click the MARK IN red, right-facing arrow. It's the one that's to the right of the "current/in/out" timing area.
Drag the scrubber to your out point and click the MARK OUT blue, left-facing arrow.
Click the green downward-facing arrow. Edited clip appears on the timeline.
Click on the original clip in the media area. Don't skip this step. The IN/OUT of the last clip you worked on will be defined by the selected area (not darkened) in the preview window.
To cut out another portion of this clip...
Move the scrubber to the new IN point.
Move the blue arrow, under the preview window (that marked the end of the prior clip that you cut out) to the right, so that it is past the point that will be your new OUT point.
Click the MARK IN button.
Move the scrubber to the new out point.
Click the MARK OUT button.
Click the green arrow to add this to the sequence.
(If you get a warning that the IN can't be before the out or the OUT can't be before the in mark, remember that your new IN/OUT marks must be set within the selected area, between the red and blue arrows.)
An interesting variation, if you want to make each clip a separate item in the media area, is to first follow the above procedure...
After marking an IN/OUT, as described above, move the scrubber to anywhere within the selected area. Note that the green SPLIT button, to the right of the green arrow, lights up.
Click on it and the clip portion that you have marked will appear as a new clip, incremented by number, in the media area - for dragging to the timeline.
