Although there aren’t any limitations in our app on how many size charts you can have. Shopify does have a limit on how many characters can be used.
Our app uses metafields to store all the data of your size charts.
Shopify has a limit of 4,000,000 characters for a metafield.
It could be an issue that you copied and pasted HTML, or images to a size chart that takes up a lot of space.
Instead of copying and pasting images please use our image uploader.
If you still need help please contact us.