What can a 200W folding panel realistically charge?

In good direct sun it can run a mid-size power station or top up phones, laptops and cameras. Real output drops with clouds, angle and heat, so expect well under the rated 200W much of the time.

Will it work with my power station?

Only if the panel's voltage and connector match your station's solar input. Check the plug type and the input voltage window before buying, since mismatches are the most common problem with portable panels.

Is monocrystalline better than polycrystalline here?

Yes for portable use. Monocrystalline cells give more power per square meter and tend to perform better in low light, which matters when you are carrying the panel.

Can I chain several panels together?

This is a single panel, so series or parallel expansion depends on the connectors and your power station's limits. Most users run it alone rather than adding a second unit.