R文件包格式更改字体大小

我使用condformat包在Rmarkdown中有条件地格式化数据帧的颜色单元格，并输出为pdf。这是预期的工作，但表是大的，我想减少字体的大小。然而，我无法在文档或谷歌中找到如何实现这一点

我使用的代码是：

condformat(df_db_time[,c("Date\\Time","h08-h09","h09-h10","h10-h11","h11-h12","h12-h13","h13-h14","h14-h15","h15-h16","h16-h17","h17-h18","h18-h19","h19-h20")]) %>%
rule_fill_gradient("h08-h09",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h09-h10",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h10-h11",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h11-h12",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h12-h13",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h13-h14",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h14-h15",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h15-h16",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h16-h17",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h17-h18",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h18-h19",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
rule_fill_gradient("h19-h20",low = rgb(1,1,1), high = rgb(1,0,0)) %>%
 condformat2latex()

先谢谢你