What is expected when submitting to a conference I am planning to submit an abstract to a conference (pure mathematics). In the webpage they have the options of filling in the title, providing a pdf file of abstract and an option of providing a "full text/other file". I am not sure about the last option. 

Do I provide one of my paper that I will talk about? That seems weird as I (most of the speakers I guess?) will be talking about a series of works. Or do I need to make a new pdf file, summarizing all the works covered? Or do I provide the beamer file? Or nothing at all? 

Is it common that when submitting an abstract to a math conference, one has to also submit a file which describe their talk in some details?
It is typical to just provide a title and abstract.  In my experience, they are usually submitted in plain text or TeX format, not even in pdf.  You are never asked to provide a paper, though for some conferences you may be asked for notes later.  Based on your question, I guess the organizers want you to submit a file that they will just link to on the webpage for an abstract, which could be a pdf or plain text.  If you're still uncertain about what to do, just ask the organizers what they prefer.