First, note that importing data from html is always going to be very iffy. html is a presentation format designed to display things to humans, it's not design for data transfer and you're going to have to remove all the presentation cruft to get at your data.
So, the first thing you should try is contacting the website to see if they have a direct interface to the underlying database.
Bearing this in mind, the following will import your data with the current format of the website. Any change, even minor to the format of that page may break the code.
%definition of patterns used to locate required information with a table row:
intpattern = '<td[^>]*>(\d+)</td>';
linkpattern = '<td[^>]*><a[^>]+>([^<]+)</a></td>';
numberpattern = '<td[^>]*>(\d+(\.\d+)?)</td>';
anypattern = '<td[^>]*>([^<]+)</td>';
emptypattern = '<td[^>]*></td>';
%read and parse html
html = webread('https://tennisabstract.com/reports/atp_elo_ratings.html');
tabledata = regexp(html, ['<tr[^>]*>', ...
intpattern, ...
linkpattern, ...
numberpattern, ...
numberpattern, ...
emptypattern, ...
numberpattern, ...
numberpattern, ...
numberpattern, ...
emptypattern, ...
anypattern, ...
numberpattern, ...
numberpattern], 'tokens');
assert(~isempty(tabledata), 'Failed to parse html according to pattern. The format of the page may have changed');
tabledata = cell2table(vertcat(tabledata{:}), 'VariableNames', {'Rank', 'Player', 'Age', 'ELO', 'Hard', 'Clay', 'Grass', 'Peak_Match', 'Peak_Age', 'Peak_ELO'});
tabledata = convertvars(tabledata, [1, 3:7, 9, 10], @str2double);
tabledata.Player = strrep(tabledata.Player, ' ', ' ')
