Issues combining ExPeX with Tabular

UPDATED

(1) A noindent at the beginning takes care of the left unwanted space.

(2) The misalignment of the hebrew lines is cause by the ascender of the Lamed. Using parbox[b] and the same settings for all three cells keeps all baselines aligned.

(3) No need to use p columns. Use begin{tabular}{|c|c|c|}

% !TeX TS-program = xelatex 

documentclass[11pt]{scrbook}

usepackage[
paperwidth=8in,
paperheight=10in,
inner=0.5in,
outer=0.5in,
bindingoffset=0.25in,
top=0.75in,
bottom=0.75in,
twoside,
showframe
]{geometry}

usepackage{scrlayer-scrpage} 
usepackage{microtype}
usepackage{booktabs,multirow,graphicx,adjustbox,makecell} 

usepackage{polyglossia}
setdefaultlanguage{english}
setotherlanguage{hebrew}
newfontfamilyhebrewfont[Script=Hebrew]{Linux Libertine O}
newfontfamilyenglishfont[Ligatures=NoCommon]{Linux Libertine O}
    
usepackage{expex}

makeatletter
define@lingincdimenkeys{numoffset,textoffset,numvoffset}
makeatother

lingset{
    everygla=LARGE, 
    everyglb=footnotesizeenglishfont,
    everyglc=footnotesizeenglishfont,
    everyglft=footnotesizeenglishfont,
    glwordalign=center,
    glhangindent=0em,
    glrightskip=0pt,
    glhangstyle=none,
    numvoffset=.3ex,   
    aboveglbskip=-0.7ex,
    aboveglcskip=-0.7ex
}

begin{document}
    
noindent   begin{tabular}{|c|c|c|} % changed<<<<<<<
    multicolumn{3}{c}{begin{LARGE}texthebrew{א־ב־ד} end{LARGE}} 
    hline
    parbox[b]{.1textwidth}{% % changed <<<<<<<   parbox bottom aligned
        begin{english}
            begingl[everygla=normalsize] 
            gla Adjective //
            endgl
        end{english}%
    }
    &
    parbox[b]{.2textwidth}{% changed <<<<<<<   parbox bottom aligned
        begin{hebrew}
            begingl
            gla אבוד //
            glb avud //
            glc lost //
            endgl
        end{hebrew}%
    } 
    &
    parbox[b]{.6textwidth}{% changed <<<<<<<   parbox bottom aligned
        begin{hebrew}
            begingl
            gla  הקורס הזה קשה, אני אבודה לגמרי. //
            glb hakurs haze kasha ani avuda legamre //
            glc textenglish{the course} textenglish{the this} difficult I lost completely //
            glft textenglish{This course is difficult, I am completely lost.} //
            endgl
        end{hebrew}%
    } 
    
    hline
end{tabular}


end{document}