At work, when I want to understand a data set (I work with portfolio data in life insurance), I would usually use pivot tables in Excel to see, for example. development of variables in time or dependencies between variables. I recalled from the university a nice R-function, where you can build each column of a data frame for every other column, for example:

issue.age , , ( ). , iss.year, "". . , ., -

, 2014 2016 .
, , , Excel.
, , , plot(data.frame)?