Unable to change lines spacing inside tabular environment

Question

I am having some trouble decreasing the length of linespace while inside the table. Some cells are going to contain quite a lot of text, and I would like to minimize the distance between the lines as much as possible, while maintaining it readable. Currently, I could fit another line in between, though I cannot figure out, how to decrease it.

Here is the line of code for table:

\begin{table}[H]
\centering
\caption{Ārējās iedarbības klases}
\label{tab:iedarb_klases}
\small
\begin{tabular}{|p{21mm}|p{59mm}|p{65mm}|}
    \hline
    \textbf{Klašu apzīmējums} & \textbf{ Vides raksturojums} & \textbf{Informatīvi piemēri, kas parāda ārējo iedarbības klašu rašānās iespējas}\\
    \hline
    \multicolumn{3}{|l|}{\textbf{1. Korozijas vai saēšanas risks nepastāv}} \\ \hline
     \textbf{X0} & Betonam bez stiegrojuma vai iebetonētametāla: Visa veida pakļaušana vides ietekmei, izņemot vietas, kur ir sasaldēšanas/atkausēšanas, abrazīvas iedarbības vai ķīmiskas iedarbības risks.\ Betonam ar stiegrojumu vai iebetonētam metālam: Ļoti sausa vide  &  \hline
     M & 43 & 7 \\ \hline
     F & 11 & 39 \\ \hline
\end{tabular} 

\end{table}

And this would be the output, from the given trial:

I am quite new to LaTeX, so I am unsure if I am also supposed to paste in all the lines from premable, or that would be unrelated to changing linespace inside table only?

Cheers!

EDIT: This would be my premable:

\usepackage{fontspec}      
\usepackage[a4paper,left=2.54cm,right=2.54cm,top=3.18cm,bottom=3.18cm]{geometry}     
\usepackage{fancyhdr}       
\usepackage{parskip}        
\usepackage{titlesec}
\usepackage{tikz}           
\usepackage{pgfplots}       
\usepackage{xcolor}         
\usepackage{amsmath}        
\usepackage{siunitx}        
\usepackage{listings}       
\PassOptionsToPackage{hyphens}{url} 
\usepackage{hyperref}       
\usepackage{cleveref}       
\usepackage{textcomp}       
\usepackage[latvian]{babel} 
\usepackage{caption}       
\usepackage{subcaption}     
\usepackage{csquotes}       
\usepackage[backend=biber,style=numeric,sorting=none]{biblatex}
\bibliography{bibliography.bib}
\usepackage{tabularx}

\usepackage{booktabs}

\usepackage{float}

\usepackage{calc}

\usepackage[printwatermark=false]{xwatermark} 
\usepackage{blindtext}
\usepackage{titling}

This is the main file:

\documentclass[a4paper,oneside,12pt]{report} %openright
\input{Setup/Statics.tex}
\input{Setup/Preamble.tex}
\input{Setup/Settings.tex}
% following lines disables hyphenation
\tolerance=1
\emergencystretch=\maxdimen
\hyphenpenalty=10000
\hbadness=10000
\begin{document}
\pagenumbering{arabic}
\input{Frontmatter/Frontpage.tex}
\pagecolor{white}
\input{Frontmatter/izpildeslapa.tex}
\input{Frontmatter/Bakalauradarbauzdevums.tex}
\input{Frontmatter/Inzenierprojektadalas.tex}
\clearpage
\clearpage 
\input{Frontmatter/Anotacija.tex}
\input{Frontmatter/Abstract.tex}
\renewcommand*\contentsname{\LARGE Saturs}
\tableofcontents
\addcontentsline{toc}{section}{Saturs}
\addtocontents{toc}{\normalsize \textbf{Bakalaura darbs}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\input{Bakalauradarbs/Ievads.tex}
\input{Bakalauradarbs/01_Kalposanas_laika_modelesana.tex}
\input{Bakalauradarbs/02_Apkartejas_vides_apstakli.tex}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\addtocontents{toc}{\normalsize \textbf{Inženierprojekts}}
\input{Inzenierprojekts/titullapa.tex}
\input{Inzenierprojekts/01_nodala.tex}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\printbibliography[heading=bibintoc,title={Izmantotā literatūra}]
\bibliographystyle{plain}
\input{Backmatter/Appendix.tex}
\end{document} 

And some of the related settings:

% Font
\setmainfont{Times New Roman}
\renewcommand\thepart{Part \Roman{part}}
\titleformat{\part}[display]{\bfseries\huge \centering}{\bfseries\Huge \thepart}{1em}{\thispagestyle{empty}}{}
\titleformat{\chapter}{\bfseries\huge}{\thechapter}{1em}{\centering}
\titleformat{\section}{\bfseries\Large}{\thesection}{12pt}{\centering}
\titleformat{\subsection}{\bfseries\large}{\thesubsection}{1em}{\centering}
\titleformat{\subsubsection}{\bfseries\normalsize}{\thesubsubsection}{1em}{\centering}
\newcommand\TitleFont[1]{{\bfseries #1}}
\newcommand\titlefont[1]{{#1}}
\urlstyle{sf}
%\def\UrlFont{\NeoSansProReg}
% Paragraph
% Table of contents (TOC) and numbering of headings
\setcounter{tocdepth}{2}    % Depth of table of content: sub sub sections will not be included in table of contents
\setcounter{secnumdepth}{2} % Depth of section numbering: sub sub sections are not numbered
\makeatletter % Reset chapter numbering for each part
@addtoreset{chapter}{part}
\makeatother
% Spacing of titles and captions
\titlespacing\chapter{0pt}{0pt plus 4pt minus 2pt}{4pt plus 2pt minus 2pt}
\titlespacing\section{0pt}{12pt plus 3pt minus 3pt}{2pt plus 1pt minus 1pt}
\titlespacing\subsection{0pt}{8pt plus 2pt minus 2pt}{0pt plus 1pt minus 1pt}
\titlespacing\subsubsection{0pt}{4pt plus 1pt minus 1pt}{-2pt plus 1pt minus 1pt}
\captionsetup{belowskip=\parskip,aboveskip=4pt plus 1pt minus 1pt}
% Setup header and footer
\cfoot{Page \thepage}
\setlength{\parindent}{4em}
\setlength{\parskip}{0em}
\renewcommand{\baselinestretch}{1.5}