In attachment cell you can put only attachment or attachments. If this cell is editable, user can remove and add attachments. If user is only reader, user can only download and see the preview. (Preview is visible, only for images and pdfs).
This cell have the same options as attachment section , article about it: https://qalcwise.zendesk.com/hc/en-us/articles/212988709-Designing-Apps-Attachment-widget