Try using tableau Reader and access views.
Tableau server is license based.
Regarding your first question:
As long as your excel file is stored in the same location, you have two option.
1) Your Tableau Workbook can be connected to the excel file with a 'live connection' this means he will update it automatically
2) Your Tableau Workbook works with an extract of the excel file. To get this updated you need to shedule a refresh extract on the Tableau Server.
Regarding your second question:
It seems to me your are referring to Tableau Reader which is totally free!
If you have some additional questions, don't hesitate to contact me.
I Know about Tableau Reader ,
but my Workbooks created through Tableau-R integration.
So,we cannot open those in Reader.
Is there any alternative?
In the official documentation of Tableau you can find the following section:
Here is a link to the full document: