下面是我采集第二个表的方法，你可以参考一下

library(RSelenium)
library(rvest)
library(stringr)
library(data.table)

remDr <-　remoteDriver(
  browserName = "chrome",
  remoteServerAddr = "localhost",
  port = 4444L
)

remDr$open()


url<-'https://www.arcgis.com/apps/webappviewer/index.html?id=2de764a9303848ffb9a4cac0bd0b1aab'  
remDr$navigate(url)


btn = remDr$findElement("xpath","//*[@id='widgets_AttributeTable_Widget_30']/div[1]")
btn$clickElement()

Sys.sleep(3)

vtn = remDr$findElement("xpath","//*[@id='dijit_layout_TabContainer_0_tablist_dijit_layout_ContentPane_1']")
vtn$clickElement()

###############################################################################################


n1 = remDr$executesc ript("return document.querySelector('#widgets_AttributeTable_Widget_30_uniqName_0_1_footer > div:nth-child(1)').innerText")[[1]]
n1 = str_extract(n1,"\\d+") %>% as.numeric()
n1

#################################################################################################
h1 = remDr$executesc ript("return document.querySelector('#dgrid_1 > div.dgrid-scroller').scrollHeight;")[[1]]
pu = round(25*h1/n1)#因为一般每次加载25个数，这里设为25，下面的循环同理，如果采集不完整变小此数

datlist = list()
j = 1
remDr$setTimeout(type = "implicit", milliseconds = 15000)#15000加载数据时间,如果采集不完整变大此数
for(i in 0:(round(n1/25))){
	
	txt = remDr$executesc ript("return document.querySelector('#dgrid_1 > div.dgrid-scroller').outerHTML")[[1]]
	wb <- read_html(txt) %>% html_table() %>%  rbindlist()
	datlist[[j]] = wb
	j = j + 1
	remDr$executesc ript(paste0("document.querySelector('#dgrid_1 > div.dgrid-scroller').scrollTo(",i*pu,',',(i+1)*pu,')'))
	Sys.sleep(2)
}

dtable = rbindlist(datlist)
unique(dtable)
dtable