{officer} is an R package that lets you extract elements of a Word document, including tables, into a tidy dataframe. I've written a function to 're-rectangularise' an extracted Word table into an R dataframe.

rectangularise-tables.R

# Functions building on the {officer} package:
#   https://davidgohel.github.io/officer/

# You can read more about these functions in a blog post:
#   https://www.rostrum.blog/2023/06/07/rectangular-officer/

# There are other solutions. You can also try {docxtractr} by Bob Rudis
# (on CRAN), which doesn't depend on {officer}, or {officerExtras} by Eli
# Pousson (on GitHub).

rectangularise_tables <- function(
    docx_summary,  # output dataframe from docx_summary
    assume_headers = TRUE,  # assume headers in first row?
    type_convert = TRUE  # try to coerce columns to most likely data type?
) {
  
  # Check inputs
  
  is_data.frame <- inherits(docx_summary, "data.frame")
  
  docx_summary_names <- c(
    "doc_index", "content_type", "style_name", "text", "level", "num_id", 
    "row_id", "is_header", "cell_id", "col_span", "row_span"
  )  # column names we can expect in the output from docx_summary
  
  is_docx_summary <- all(names(docx_summary) %in% docx_summary_names)
  
  if (!is_data.frame | !is_docx_summary) {
    stop(
      paste(
        "Argument 'docx_summary' must be a data.frame created with",
        "'officer::docx_summary'."
      ),
      call. = FALSE
    )
  }
  
  # Get only the rows that relate to Word tables
  docx_summary_tables <- 
    docx_summary[docx_summary[["content_type"]] %in% "table cell", ]
  
  # Get the ID value for each Word table
  doc_indices <- unique(docx_summary_tables[["doc_index"]])
  
  # Initiate an empty list to hold dataframe representations of the Word tables
  tables_out <- vector(mode = "list", length = length(doc_indices))
  names(tables_out) <- paste0("doc_index_", doc_indices)
  
  # For each Word table, 'rectangularise' into a dataframe and add to the list
  for (doc_index in doc_indices) {
    
    docx_summary_table <- 
      docx_summary_tables[docx_summary_tables[["doc_index"]] == doc_index, ]
    
    extracted_table <- .rectangularise_table(docx_summary_table, assume_headers)
    
    list_element_name <- paste0("doc_index_", doc_index)
    tables_out[[list_element_name]] <- extracted_table
    
  }
  
  # Optionally convert columns to appropriate type (integer, etc)
  if (type_convert) {
    tables_out <- lapply(tables_out, type.convert, as.is = TRUE)
  }
  
  return(tables_out)
  
}

.rectangularise_table <- function(
    table_cells,  # docx_summary output filtered for 'table cells' only
    assume_headers = TRUE  # assume headers in first row?
) {
  
  # Check inputs
  
  is_table_cells <- all(table_cells[["content_type"]] == "table cell")
  is_one_table <- length(unique(table_cells[["doc_index"]])) == 1
  
  if (!is_table_cells | !is_one_table) {
    stop(
      paste(
        "Argument 'table_cells' must be a dataframe created with",
        "'officer::docx_summary' where 'content_type' is filtered for",
        "'table cell' only."
      ),
      call. = FALSE
    )
  }
  
  # Split each Word table into a list element, isolate headers and cell contents
  cell_id_split <- split(table_cells, table_cells[["cell_id"]])
  headers <- lapply(cell_id_split, function(x) x[x[["is_header"]], "text"])
  content <- lapply(cell_id_split, function(x) x[!x[["is_header"]], "text"])
  table_out <- as.data.frame(content)
  
  # Column headers are identified by TRUE in the is_header column, but may not
  # be marked up as such. Use them as dataframe headers if they exist.
  has_headers <- length(unlist(headers)) > 0
  if (has_headers) {
    names(table_out) <- headers
  }
  
  # If headers are not identified by is_header, assume that the first row of the
  # Word table contains the headers. The user can control this behaviour with
  # the argument assume_headers.
  if (!has_headers & assume_headers) {
    headers <- table_out[1, ]  # assume first row is headers
    table_out <- table_out[2:nrow(table_out), ]  # rest of table is content
    names(table_out) <- headers
  }
  
  return(table_out)
  
}