How can I get the largest MB and highest picture quality from my Panasonic TZ100

Some points for explanation:

• File size in jpg files is not an indicator for quality of the images. It is just a measure which is influenced by amount of pixels multiplied by the factor how good the image can be compressed. You could e.g. add noise to your image, this would increase file size, but decrease quality.

• What you are looking for is optical resolution. This is dictated by several factors as well, like optical resolution of the lens (sharpness, correction of aberrations), optical resolution of the sensor (might by limited due to anti aliasing filters), pixel resolution of the sensor (megapixels), and signal to noise ratio of the sensor.

• Small sensors with high resolution usually have a disadvantage in low light and will produce more ISO noise in low light situations.However, in your case, you are doing product photography, so you could get your scene perfectly lit. So ISO noise should not be a problem. Use the native ISO of you sensor, which is ISO 125 for this camera.

• The factor that will determine if your images look good is mainly technically limited by the sharpness and optical quality of the lens you are using. As this is not an interchangeable lens, you have to try if it is sufficient.

• If you are absolutely needing more resolution and your files are of good quality, then you can just increase resolution in photoshop and resharpen a bit. However, there are limits. Some services offer AI-based resolution boosting. However, an image will never be better than the image you start with.

• If you really want the best possible quality product shots, you WILL have to learn how to develop and correct RAW files and do post processing in an application like photoshop, affinity photo, gimp or similar. And you might get to the point where you come to the conclusion, that the camera is the limiting factor.

• You will need need good light and a tripod to minimize camera shake. As the camera has no way to drive external flashes, I would recommend daylight balanced LED constant lights of good quality plus softboxes. You might be able to use a light tent to minimize unwanted reflections from your environment.

• And just to manage your expectations: Usually product photography uses high-end cameras in the price range of about 10x the cost of the camera you are using plus a high-end macro lens. The lighting setup would include several strobes or constant lights, different light formers to produce pleasant light, probably multiple shots of the product that are finally combined and cleaned up in a tedious post production process in Photoshop to get rid of any unwanted reflection. If the object is very small, even dozens of images might be needed to be joined in a process called focus stacking to achieve decent sharpness. This does not mean you cannot get good photos out of a compact camera, but you will run into limits.

While the Panasonic TZ100 is a capable camera, your expectations of it are too high. It's 20 MP is much better than typical 1/2.3" used in other compact camera but, even at its best, it will have trouble producing an A2-size print.

To maximize image quality from the TZ100:

• Use ISO 125, which is the native ISO of its sensor and shows the least amount of noise while preserving all the dynamic-range the sensor can capture.
• Use plenty of light. Since you are in a controlled environment add as much light as you can.
• Most lens sharpen up when stopped down a little but stopping down too much gets you past the diffraction limit. With that lens, you get the best sharpness at F/5.6 with the lens at its widest. So, get as close to the subject as you can so that you can use a wider focal-length and stop down 2-stops from wide-open.
• Use a tripod.