First, when you hide columns in Excel (by right-clicking the relevant column or columns, and clicking "Hide"), it's easy for you or others to forget that the spreadsheet contains ...

Each cell has its own number format, which you can see by selecting a cell and seeing the Number group in the Home tab on the ribbon. For some data types, such as a date or a percentage ...

Excel's JSON import tools can now load the data, but you're going to have to construct a data transformation to get at the information you want. In the Data section of the ribbon choose Get Data ...