Kontakt offers plenty of ways to model the playback of Your samples. To just pick up one feature I´d like to
explain the way to let KONTAKT play Your samples in a Forward-backward-loop. This looping style is also known as  Ping-pong-looping.

First step in an empty KONTAKT rack ist to select a Sample and drag it into the Rack. I just took a single tambourine hit from a drum Sample library.

Now open the Edit window for the instrument.

In the Source section select “sampler” sample playback mode.

In the Editor panel press the Wave Editor button.

The Wave Editor opens up.

The Sample Loop tab of the Wave Editor is split into a number of loop selection buttons, and
a parameter view for the currently selected loop region.

Activate the Sample Loop feature by clicking the small “power button” icon to the left of the tab title.

Click on Loop #1 and move over to the loop mode button.

A drop-down menu opens up. You can choose between several different
loop characteristics. In addition to the displayed entry, the selected behavior
is depicted with an illustration above the menu. KONTAKT provides the
following loop behaviors:

• Until End: KONTAKT will play the loop in a forward direction.
  The loop will keep playing during your amplitude envelope’s release
  phase, if any.
• Until End <->: KONTAKT will play the loop in alternating forward and
  backward directions (“ping-pong loop”). The loop will keep playing
  during the release phase of your sound.
• Until Release: KONTAKT will play the loop in a forward direction as
  long as the key is being held. When it’s released, it will resume normal
  playback of the Sample, starting from the current playback position.
• Until Release <->: Like Until Release, but with an alternating forward
  and backward playback direction during the loop.
• One Shot: If the first loop region of your Sample is set to this mode,
  KONTAKT will ignore all other active loop regions and play the Sample
  in its entirety when it’s triggered, without stopping at note-off events.

As we would like to play the sample “ping-pong-style”, choose “until End <->” an Off You Go!
Instant Ping-pong-tambourine!

This is of course a pretty rough way to get those ping-pongs. So please play around with all the other options available in the Wave Editor to tweak the loop section or the sample itself to Your needs.