To fully understand the problem, you'll need to know what encoding your database uses (for ex MySQL has "latin1_swedish" by default), and what functions you used to read or import your database content (readLines() has an encoding option).
Anyway, based on the context I think in your rows "\x97" (and "\u0097" in column names) is supposed to be o with acute accent (ó). This is unusual, as in Unicode it would be "\u00f3". We can go to a bigger list that suggests the encoding here is the (old) Macintosh (nowadays Apple also switched to UTF-8). So we can convert your text:
x <- "\x97"
x
#> [1] "—" # not the character we expect
xx <- iconv(x, "mac", "UTF-8")
xx
#> [1] "ó"
Encoding(c(x, xx))
#> [1] "unknown" "UTF-8"
You can see the full list of conversions that iconv() supports with iconvlist(). Note the Encoding() only supports "latin1", "UTF-8" and "unknown" (and a special "bytes"), so you can't use Encoding(x) <- "mac" as one could have thought.
In the column headers, the character appears as "\u0097" which does get translated as "¬ó" (I don't know why it's not the same as in the rows, might depend on the source and functions used). You can always replace it selectively with:
str_replace(x, "\u0097", "\x97")
And then run iconv(). Or to directly go to Unicode:
str_replace(x, "\u0097", "\U00f3")