To add to what oeaulong is saying:
The New Image dialog is used to create either (a) a new blank image or (b) a new image for existing image data (tiles) already prepared and stored in a table. The latter primarily occurs when you are creating image data using a query, the New Image dialog allows quickly creating a new component to view that data in case you forgot to create such a component programmatically.
In your case, there's no image data just yet, you want to create it. 9 can do this in a variety of ways, the one that best fits your scenario is interpolating a drawing. So, you have to create a drawing and then you can run a transform that will take that drawing and interpolate it into a new image, generating tiles. In order to create a drawing, you have to have a geometry field. Your data doesn't have one, but it has fields for latitude / longitude, you can compose geometry data from them. This is also done using a transform.
For details, see the video linked above. Or see examples in Help.