带有下拉菜单的Python Dash应用程序，用于选择Excel文件表并在表格中显示

I am in the process of learning Dash with the final goal being the development of an app that allows quick analysis of data sets in an excel file. I'd like a drop down menu that will allow for switching between the sheets in the excel file. I'm having trouble getting this to run properly. I can make it output to a graph but not a table. My code is as follows:I am in the process of learning Dash with the f