Shiny App Demo with 2 files

server.R

library(shiny)

server<-(function(input, output){
  output$tableContents<-renderTable({
    inFile<-input$fileNameWithPath
    if (is.null(inFile))
      return(NULL)
    read.csv(inFile$datapath, header = input$inputHeader, sep=input$inputSep, quote = input$inputQuote)
  })
})
shinyApp(ui, server)

ui.R

library(shiny)

ui<-(fluidPage(
  titlePanel("Uploading Files"),
  sidebarLayout(
    sidebarPanel(
      fileInput('fileNameWidthPath','Choose CSV File', accept = c('text/csv','text/comma-separated-values,text/plain','.csv')),
      tags$hr(),
      tags$h1("Hello:"),
      checkboxInput('inputHeader', 'Header', T),
      tags$hr(),
      radioButtons('inputSep','Separator',
                   c(Comma=',', Semicolon=';', Tab='\t'),','),
      radioButtons('inputQuote','Quote',
                   c(None=',', 'Double Quote'='"', 'Single Quote'="'"), '"')
    ),
    mainPanel(
      tableOutput('tableContents')
    )
  )
))