The chart picture opened in Photoshop shows an image size of 2550 x 3300 pixels and is very sharp.
That's a huge size compared to a video frame. When you resize it to standard video frame size, you won't have anywhere near that resolution and it will be fuzzier. You'll get the best results if you resize it in Photoshop without flattening the image first (you want the text layers to remain as text layers and not be rasterized) and then save it. If you save the file as a jpg at 2550x3300 and then scale it in premiere, the text will have been rasterized before scaling and it will look a mess. Don't expect miracles. If it doesn't look good in Photoshop at 640x480, it won't look good in premiere either.