When I put a data frame into a cell, it shows only some of the rows, with a "..." in the middle.
Edit: I'm looking for R equivalents of these Python notebook calls:
import pandas
# "If max_cols is exceeded, switch to truncate view"
pandas.set_option('display.max_columns', 5400)
# "The maximum width in characters of a column"
pandas.set_option('display.max_colwidth', 500)
See also http://pandas.pydata.org/pandas-docs/stable/generated/pandas.set_option.html.