This plugin will add completion for the values of an arbitrary column of a csv-file.

{
  'PhilippFeO/cmp-csv',
  opts = {
    -- see below
  }
}

There are currently two options, one, csv_path, is mandatory.

require('cmp-csv').setup({
  documentation_format = '',
  csv_path = '' -- No csv, no party 😞
  filetype = '',
  completion_column = 1,
  skip_rows = 0
})

• documentation_format: Lua format string, should contain three %s. No checks are performed, example: %s (Col 1)\n%s (Col 2)\n%s (Col 3).
• csv_path: Path to the csv-file to generated sources for nvim-cmp. Without a csv-file no sources can be established and setup() will fail. No consistency checks for the csv are performed¹.
• filetype: In which buffers we wish to have the completion.
• completion_column: Which column of your CSV is used for syntax completion. If it exceeds the number of values in one row, an error is thrown.
• skip_rows: First rows to skip in case there are header information. An error is thrown if skip_rows exceeds the line number of csv_path.

require("cmp").setup({
  sources = {
    { name = "cmp_csv" }, -- '_' not '-' 😯
  }
})

• TJ DeVires video on nvim-cmp was a great help and is an inspiration: TakeTuesday E01: nvim-cmp