To export data from the Product Gallery first check off any products you want to export data for by clicking the box in the upper left corner of the Product image
You can check one product, a dozen products, or use the "Select All" checkbox in the drop down bar to check many items at once.
Next, click the menu icon in the upper right corner next to "actions" - it appears as the three vertical dots.
One of the available options is to "Export". If you click this, a popup will appear to specify the file format you want the data downloaded as.
After selecting your choices click the "Export" button. This then will download to your desktop.