Select the start and end paths....

Choose `Object > Blend > Make`

Then

Choose `Object > Blend > Blend Options` and set the drop down menu to **Specified Steps** and enter 8 in the text field -- 8 because you start with 2 thus resulting in 10 steps including start and end.

[![enter image description here][1]][1]

Leaving the blend in tact means if you move *either* path at the end with the Direct Selection tool (white arrow), the spacing will adjust to accommodate any repositioning. 

If you want each step to be an individual, selectable, path - Choose `Object > Expand`. When the Expand Options window pops up, tick *only* the **Object** option and hit the <kbd>OK</kbd> button. Then you may need to also ungroup.

  [1]: https://i.sstatic.net/jjIx2.png